^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0-or-later
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /* Common capabilities, needed by capability.o.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) #include <linux/capability.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) #include <linux/audit.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) #include <linux/init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include <linux/lsm_hooks.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <linux/file.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/mm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/mman.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <linux/pagemap.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <linux/swap.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <linux/skbuff.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include <linux/netlink.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include <linux/ptrace.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include <linux/xattr.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #include <linux/hugetlb.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) #include <linux/mount.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) #include <linux/sched.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) #include <linux/prctl.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) #include <linux/securebits.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) #include <linux/user_namespace.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) #include <linux/binfmts.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) #include <linux/personality.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) * If a non-root user executes a setuid-root binary in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) * !secure(SECURE_NOROOT) mode, then we raise capabilities.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) * However if fE is also set, then the intent is for only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) * the file capabilities to be applied, and the setuid-root
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) * bit is left on either to change the uid (plausible) or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) * to get full privilege on a kernel without file capabilities
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) * support. So in that case we do not raise capabilities.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) * Warn if that happens, once per boot.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) static void warn_setuid_and_fcaps_mixed(const char *fname)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) static int warned;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) if (!warned) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) printk(KERN_INFO "warning: `%s' has both setuid-root and"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) " effective capabilities. Therefore not raising all"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) " capabilities.\n", fname);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) warned = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) * cap_capable - Determine whether a task has a particular effective capability
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) * @cred: The credentials to use
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) * @ns: The user namespace in which we need the capability
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) * @cap: The capability to check for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) * @opts: Bitmask of options defined in include/linux/security.h
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) * Determine whether the nominated task has the specified capability amongst
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) * its effective set, returning 0 if it does, -ve if it does not.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) * NOTE WELL: cap_has_capability() cannot be used like the kernel's capable()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) * and has_capability() functions. That is, it has the reverse semantics:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) * cap_has_capability() returns 0 when a task has a capability, but the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) * kernel's capable() and has_capability() returns 1 for this case.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) int cap_capable(const struct cred *cred, struct user_namespace *targ_ns,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) int cap, unsigned int opts)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) struct user_namespace *ns = targ_ns;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) /* See if cred has the capability in the target user namespace
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) * by examining the target user namespace and all of the target
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) * user namespace's parents.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) for (;;) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) /* Do we have the necessary capabilities? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) if (ns == cred->user_ns)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) return cap_raised(cred->cap_effective, cap) ? 0 : -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) * If we're already at a lower level than we're looking for,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) * we're done searching.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) if (ns->level <= cred->user_ns->level)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) return -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) * The owner of the user namespace in the parent of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) * user namespace has all caps.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) if ((ns->parent == cred->user_ns) && uid_eq(ns->owner, cred->euid))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) * If you have a capability in a parent user ns, then you have
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) * it over all children user namespaces as well.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) ns = ns->parent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) /* We never get here */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) * cap_settime - Determine whether the current process may set the system clock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) * @ts: The time to set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) * @tz: The timezone to set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) * Determine whether the current process may set the system clock and timezone
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) * information, returning 0 if permission granted, -ve if denied.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) int cap_settime(const struct timespec64 *ts, const struct timezone *tz)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) if (!capable(CAP_SYS_TIME))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) return -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) * cap_ptrace_access_check - Determine whether the current process may access
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) * another
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) * @child: The process to be accessed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) * @mode: The mode of attachment.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) * If we are in the same or an ancestor user_ns and have all the target
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) * task's capabilities, then ptrace access is allowed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) * If we have the ptrace capability to the target user_ns, then ptrace
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) * access is allowed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) * Else denied.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) * Determine whether a process may access another, returning 0 if permission
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) * granted, -ve if denied.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) int cap_ptrace_access_check(struct task_struct *child, unsigned int mode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) int ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) const struct cred *cred, *child_cred;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) const kernel_cap_t *caller_caps;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) rcu_read_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) cred = current_cred();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) child_cred = __task_cred(child);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) if (mode & PTRACE_MODE_FSCREDS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) caller_caps = &cred->cap_effective;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) caller_caps = &cred->cap_permitted;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) if (cred->user_ns == child_cred->user_ns &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) cap_issubset(child_cred->cap_permitted, *caller_caps))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) if (ns_capable(child_cred->user_ns, CAP_SYS_PTRACE))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) ret = -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) rcu_read_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) * cap_ptrace_traceme - Determine whether another process may trace the current
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) * @parent: The task proposed to be the tracer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) * If parent is in the same or an ancestor user_ns and has all current's
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) * capabilities, then ptrace access is allowed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) * If parent has the ptrace capability to current's user_ns, then ptrace
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) * access is allowed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) * Else denied.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) * Determine whether the nominated task is permitted to trace the current
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) * process, returning 0 if permission is granted, -ve if denied.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) int cap_ptrace_traceme(struct task_struct *parent)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) int ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) const struct cred *cred, *child_cred;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) rcu_read_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) cred = __task_cred(parent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) child_cred = current_cred();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) if (cred->user_ns == child_cred->user_ns &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) cap_issubset(child_cred->cap_permitted, cred->cap_permitted))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) if (has_ns_capability(parent, child_cred->user_ns, CAP_SYS_PTRACE))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) ret = -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) rcu_read_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) * cap_capget - Retrieve a task's capability sets
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) * @target: The task from which to retrieve the capability sets
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) * @effective: The place to record the effective set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) * @inheritable: The place to record the inheritable set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) * @permitted: The place to record the permitted set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) * This function retrieves the capabilities of the nominated task and returns
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) * them to the caller.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) int cap_capget(struct task_struct *target, kernel_cap_t *effective,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) kernel_cap_t *inheritable, kernel_cap_t *permitted)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) const struct cred *cred;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) /* Derived from kernel/capability.c:sys_capget. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) rcu_read_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) cred = __task_cred(target);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) *effective = cred->cap_effective;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) *inheritable = cred->cap_inheritable;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) *permitted = cred->cap_permitted;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) rcu_read_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) * Determine whether the inheritable capabilities are limited to the old
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) * permitted set. Returns 1 if they are limited, 0 if they are not.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) static inline int cap_inh_is_capped(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) /* they are so limited unless the current task has the CAP_SETPCAP
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) * capability
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) if (cap_capable(current_cred(), current_cred()->user_ns,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) CAP_SETPCAP, CAP_OPT_NONE) == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) * cap_capset - Validate and apply proposed changes to current's capabilities
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) * @new: The proposed new credentials; alterations should be made here
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) * @old: The current task's current credentials
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) * @effective: A pointer to the proposed new effective capabilities set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) * @inheritable: A pointer to the proposed new inheritable capabilities set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) * @permitted: A pointer to the proposed new permitted capabilities set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) * This function validates and applies a proposed mass change to the current
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) * process's capability sets. The changes are made to the proposed new
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) * credentials, and assuming no error, will be committed by the caller of LSM.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) int cap_capset(struct cred *new,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) const struct cred *old,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) const kernel_cap_t *effective,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) const kernel_cap_t *inheritable,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) const kernel_cap_t *permitted)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) if (cap_inh_is_capped() &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) !cap_issubset(*inheritable,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) cap_combine(old->cap_inheritable,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) old->cap_permitted)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) /* incapable of using this inheritable set */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) return -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) if (!cap_issubset(*inheritable,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) cap_combine(old->cap_inheritable,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) old->cap_bset)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) /* no new pI capabilities outside bounding set */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) return -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) /* verify restrictions on target's new Permitted set */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) if (!cap_issubset(*permitted, old->cap_permitted))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) return -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) /* verify the _new_Effective_ is a subset of the _new_Permitted_ */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) if (!cap_issubset(*effective, *permitted))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) return -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) new->cap_effective = *effective;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) new->cap_inheritable = *inheritable;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) new->cap_permitted = *permitted;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) * Mask off ambient bits that are no longer both permitted and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) * inheritable.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) new->cap_ambient = cap_intersect(new->cap_ambient,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) cap_intersect(*permitted,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) *inheritable));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) if (WARN_ON(!cap_ambient_invariant_ok(new)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) * cap_inode_need_killpriv - Determine if inode change affects privileges
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) * @dentry: The inode/dentry in being changed with change marked ATTR_KILL_PRIV
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) * Determine if an inode having a change applied that's marked ATTR_KILL_PRIV
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) * affects the security markings on that inode, and if it is, should
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) * inode_killpriv() be invoked or the change rejected.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) * Returns 1 if security.capability has a value, meaning inode_killpriv()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) * is required, 0 otherwise, meaning inode_killpriv() is not required.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) int cap_inode_need_killpriv(struct dentry *dentry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) struct inode *inode = d_backing_inode(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) int error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) error = __vfs_getxattr(dentry, inode, XATTR_NAME_CAPS, NULL, 0,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) XATTR_NOSECURITY);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) return error > 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) * cap_inode_killpriv - Erase the security markings on an inode
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) * @dentry: The inode/dentry to alter
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) * Erase the privilege-enhancing security markings on an inode.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) * Returns 0 if successful, -ve on error.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) int cap_inode_killpriv(struct dentry *dentry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) int error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) error = __vfs_removexattr(dentry, XATTR_NAME_CAPS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) if (error == -EOPNOTSUPP)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) error = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) return error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) static bool rootid_owns_currentns(kuid_t kroot)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) struct user_namespace *ns;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) if (!uid_valid(kroot))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) for (ns = current_user_ns(); ; ns = ns->parent) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) if (from_kuid(ns, kroot) == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) if (ns == &init_user_ns)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) static __u32 sansflags(__u32 m)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) return m & ~VFS_CAP_FLAGS_EFFECTIVE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) static bool is_v2header(size_t size, const struct vfs_cap_data *cap)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) if (size != XATTR_CAPS_SZ_2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) return sansflags(le32_to_cpu(cap->magic_etc)) == VFS_CAP_REVISION_2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) static bool is_v3header(size_t size, const struct vfs_cap_data *cap)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) if (size != XATTR_CAPS_SZ_3)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) return sansflags(le32_to_cpu(cap->magic_etc)) == VFS_CAP_REVISION_3;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) * getsecurity: We are called for security.* before any attempt to read the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) * xattr from the inode itself.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) * This gives us a chance to read the on-disk value and convert it. If we
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) * return -EOPNOTSUPP, then vfs_getxattr() will call the i_op handler.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) * Note we are not called by vfs_getxattr_alloc(), but that is only called
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) * by the integrity subsystem, which really wants the unconverted values -
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) * so that's good.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) int cap_inode_getsecurity(struct inode *inode, const char *name, void **buffer,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) bool alloc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) int size, ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) kuid_t kroot;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) u32 nsmagic, magic;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) uid_t root, mappedroot;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) char *tmpbuf = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) struct vfs_cap_data *cap;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) struct vfs_ns_cap_data *nscap = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) struct dentry *dentry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) struct user_namespace *fs_ns;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) if (strcmp(name, "capability") != 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) return -EOPNOTSUPP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) dentry = d_find_any_alias(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) if (!dentry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) size = sizeof(struct vfs_ns_cap_data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) ret = (int) vfs_getxattr_alloc(dentry, XATTR_NAME_CAPS,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) &tmpbuf, size, GFP_NOFS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) dput(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) if (ret < 0 || !tmpbuf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) fs_ns = inode->i_sb->s_user_ns;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) cap = (struct vfs_cap_data *) tmpbuf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) if (is_v2header((size_t) ret, cap)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) root = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) } else if (is_v3header((size_t) ret, cap)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) nscap = (struct vfs_ns_cap_data *) tmpbuf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) root = le32_to_cpu(nscap->rootid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) size = -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) goto out_free;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) kroot = make_kuid(fs_ns, root);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) /* If the root kuid maps to a valid uid in current ns, then return
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) * this as a nscap. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) mappedroot = from_kuid(current_user_ns(), kroot);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) if (mappedroot != (uid_t)-1 && mappedroot != (uid_t)0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416) size = sizeof(struct vfs_ns_cap_data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) if (alloc) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) if (!nscap) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) /* v2 -> v3 conversion */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) nscap = kzalloc(size, GFP_ATOMIC);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) if (!nscap) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) size = -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) goto out_free;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425) nsmagic = VFS_CAP_REVISION_3;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426) magic = le32_to_cpu(cap->magic_etc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427) if (magic & VFS_CAP_FLAGS_EFFECTIVE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428) nsmagic |= VFS_CAP_FLAGS_EFFECTIVE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429) memcpy(&nscap->data, &cap->data, sizeof(__le32) * 2 * VFS_CAP_U32);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430) nscap->magic_etc = cpu_to_le32(nsmagic);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432) /* use allocated v3 buffer */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433) tmpbuf = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435) nscap->rootid = cpu_to_le32(mappedroot);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) *buffer = nscap;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438) goto out_free;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441) if (!rootid_owns_currentns(kroot)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442) size = -EOVERFLOW;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443) goto out_free;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446) /* This comes from a parent namespace. Return as a v2 capability */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) size = sizeof(struct vfs_cap_data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448) if (alloc) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449) if (nscap) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450) /* v3 -> v2 conversion */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451) cap = kzalloc(size, GFP_ATOMIC);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452) if (!cap) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453) size = -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454) goto out_free;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456) magic = VFS_CAP_REVISION_2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457) nsmagic = le32_to_cpu(nscap->magic_etc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458) if (nsmagic & VFS_CAP_FLAGS_EFFECTIVE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459) magic |= VFS_CAP_FLAGS_EFFECTIVE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460) memcpy(&cap->data, &nscap->data, sizeof(__le32) * 2 * VFS_CAP_U32);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461) cap->magic_etc = cpu_to_le32(magic);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463) /* use unconverted v2 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) tmpbuf = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466) *buffer = cap;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468) out_free:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469) kfree(tmpbuf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 470) return size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 471) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 472)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 473) static kuid_t rootid_from_xattr(const void *value, size_t size,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 474) struct user_namespace *task_ns)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 475) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 476) const struct vfs_ns_cap_data *nscap = value;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 477) uid_t rootid = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 478)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 479) if (size == XATTR_CAPS_SZ_3)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 480) rootid = le32_to_cpu(nscap->rootid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 481)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 482) return make_kuid(task_ns, rootid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 483) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 484)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 485) static bool validheader(size_t size, const struct vfs_cap_data *cap)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 486) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 487) return is_v2header(size, cap) || is_v3header(size, cap);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 488) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 489)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 490) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 491) * User requested a write of security.capability. If needed, update the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 492) * xattr to change from v2 to v3, or to fixup the v3 rootid.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 493) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 494) * If all is ok, we return the new size, on error return < 0.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 495) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 496) int cap_convert_nscap(struct dentry *dentry, void **ivalue, size_t size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 497) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 498) struct vfs_ns_cap_data *nscap;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 499) uid_t nsrootid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 500) const struct vfs_cap_data *cap = *ivalue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 501) __u32 magic, nsmagic;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 502) struct inode *inode = d_backing_inode(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 503) struct user_namespace *task_ns = current_user_ns(),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 504) *fs_ns = inode->i_sb->s_user_ns;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 505) kuid_t rootid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 506) size_t newsize;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 507)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 508) if (!*ivalue)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 509) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 510) if (!validheader(size, cap))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 511) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 512) if (!capable_wrt_inode_uidgid(inode, CAP_SETFCAP))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 513) return -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 514) if (size == XATTR_CAPS_SZ_2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 515) if (ns_capable(inode->i_sb->s_user_ns, CAP_SETFCAP))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 516) /* user is privileged, just write the v2 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 517) return size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 518)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 519) rootid = rootid_from_xattr(*ivalue, size, task_ns);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 520) if (!uid_valid(rootid))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 521) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 522)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 523) nsrootid = from_kuid(fs_ns, rootid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 524) if (nsrootid == -1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 525) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 526)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 527) newsize = sizeof(struct vfs_ns_cap_data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 528) nscap = kmalloc(newsize, GFP_ATOMIC);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 529) if (!nscap)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 530) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 531) nscap->rootid = cpu_to_le32(nsrootid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 532) nsmagic = VFS_CAP_REVISION_3;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 533) magic = le32_to_cpu(cap->magic_etc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 534) if (magic & VFS_CAP_FLAGS_EFFECTIVE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 535) nsmagic |= VFS_CAP_FLAGS_EFFECTIVE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 536) nscap->magic_etc = cpu_to_le32(nsmagic);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 537) memcpy(&nscap->data, &cap->data, sizeof(__le32) * 2 * VFS_CAP_U32);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 538)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 539) kvfree(*ivalue);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 540) *ivalue = nscap;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 541) return newsize;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 542) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 543)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 544) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 545) * Calculate the new process capability sets from the capability sets attached
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 546) * to a file.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 547) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 548) static inline int bprm_caps_from_vfs_caps(struct cpu_vfs_cap_data *caps,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 549) struct linux_binprm *bprm,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 550) bool *effective,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 551) bool *has_fcap)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 552) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 553) struct cred *new = bprm->cred;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 554) unsigned i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 555) int ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 556)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 557) if (caps->magic_etc & VFS_CAP_FLAGS_EFFECTIVE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 558) *effective = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 559)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 560) if (caps->magic_etc & VFS_CAP_REVISION_MASK)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 561) *has_fcap = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 562)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 563) CAP_FOR_EACH_U32(i) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 564) __u32 permitted = caps->permitted.cap[i];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 565) __u32 inheritable = caps->inheritable.cap[i];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 566)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 567) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 568) * pP' = (X & fP) | (pI & fI)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 569) * The addition of pA' is handled later.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 570) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 571) new->cap_permitted.cap[i] =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 572) (new->cap_bset.cap[i] & permitted) |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 573) (new->cap_inheritable.cap[i] & inheritable);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 574)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 575) if (permitted & ~new->cap_permitted.cap[i])
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 576) /* insufficient to execute correctly */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 577) ret = -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 578) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 579)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 580) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 581) * For legacy apps, with no internal support for recognizing they
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 582) * do not have enough capabilities, we return an error if they are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 583) * missing some "forced" (aka file-permitted) capabilities.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 584) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 585) return *effective ? ret : 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 586) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 587)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 588) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 589) * Extract the on-exec-apply capability sets for an executable file.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 590) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 591) int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data *cpu_caps)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 592) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 593) struct inode *inode = d_backing_inode(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 594) __u32 magic_etc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 595) unsigned tocopy, i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 596) int size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 597) struct vfs_ns_cap_data data, *nscaps = &data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 598) struct vfs_cap_data *caps = (struct vfs_cap_data *) &data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 599) kuid_t rootkuid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 600) struct user_namespace *fs_ns;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 601)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 602) memset(cpu_caps, 0, sizeof(struct cpu_vfs_cap_data));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 603)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 604) if (!inode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 605) return -ENODATA;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 606)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 607) fs_ns = inode->i_sb->s_user_ns;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 608) size = __vfs_getxattr((struct dentry *)dentry, inode,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 609) XATTR_NAME_CAPS, &data, XATTR_CAPS_SZ,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 610) XATTR_NOSECURITY);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 611) if (size == -ENODATA || size == -EOPNOTSUPP)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 612) /* no data, that's ok */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 613) return -ENODATA;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 614)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 615) if (size < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 616) return size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 617)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 618) if (size < sizeof(magic_etc))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 619) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 620)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 621) cpu_caps->magic_etc = magic_etc = le32_to_cpu(caps->magic_etc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 622)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 623) rootkuid = make_kuid(fs_ns, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 624) switch (magic_etc & VFS_CAP_REVISION_MASK) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 625) case VFS_CAP_REVISION_1:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 626) if (size != XATTR_CAPS_SZ_1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 627) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 628) tocopy = VFS_CAP_U32_1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 629) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 630) case VFS_CAP_REVISION_2:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 631) if (size != XATTR_CAPS_SZ_2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 632) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 633) tocopy = VFS_CAP_U32_2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 634) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 635) case VFS_CAP_REVISION_3:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 636) if (size != XATTR_CAPS_SZ_3)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 637) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 638) tocopy = VFS_CAP_U32_3;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 639) rootkuid = make_kuid(fs_ns, le32_to_cpu(nscaps->rootid));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 640) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 641)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 642) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 643) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 644) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 645) /* Limit the caps to the mounter of the filesystem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 646) * or the more limited uid specified in the xattr.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 647) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 648) if (!rootid_owns_currentns(rootkuid))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 649) return -ENODATA;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 650)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 651) CAP_FOR_EACH_U32(i) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 652) if (i >= tocopy)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 653) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 654) cpu_caps->permitted.cap[i] = le32_to_cpu(caps->data[i].permitted);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 655) cpu_caps->inheritable.cap[i] = le32_to_cpu(caps->data[i].inheritable);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 656) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 657)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 658) cpu_caps->permitted.cap[CAP_LAST_U32] &= CAP_LAST_U32_VALID_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 659) cpu_caps->inheritable.cap[CAP_LAST_U32] &= CAP_LAST_U32_VALID_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 660)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 661) cpu_caps->rootid = rootkuid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 662)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 663) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 664) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 665)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 666) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 667) * Attempt to get the on-exec apply capability sets for an executable file from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 668) * its xattrs and, if present, apply them to the proposed credentials being
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 669) * constructed by execve().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 670) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 671) static int get_file_caps(struct linux_binprm *bprm, struct file *file,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 672) bool *effective, bool *has_fcap)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 673) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 674) int rc = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 675) struct cpu_vfs_cap_data vcaps;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 676)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 677) cap_clear(bprm->cred->cap_permitted);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 678)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 679) if (!file_caps_enabled)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 680) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 681)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 682) if (!mnt_may_suid(file->f_path.mnt))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 683) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 684)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 685) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 686) * This check is redundant with mnt_may_suid() but is kept to make
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 687) * explicit that capability bits are limited to s_user_ns and its
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 688) * descendants.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 689) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 690) if (!current_in_userns(file->f_path.mnt->mnt_sb->s_user_ns))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 691) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 692)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 693) rc = get_vfs_caps_from_disk(file->f_path.dentry, &vcaps);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 694) if (rc < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 695) if (rc == -EINVAL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 696) printk(KERN_NOTICE "Invalid argument reading file caps for %s\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 697) bprm->filename);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 698) else if (rc == -ENODATA)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 699) rc = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 700) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 701) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 702)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 703) rc = bprm_caps_from_vfs_caps(&vcaps, bprm, effective, has_fcap);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 704)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 705) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 706) if (rc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 707) cap_clear(bprm->cred->cap_permitted);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 708)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 709) return rc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 710) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 711)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 712) static inline bool root_privileged(void) { return !issecure(SECURE_NOROOT); }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 713)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 714) static inline bool __is_real(kuid_t uid, struct cred *cred)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 715) { return uid_eq(cred->uid, uid); }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 716)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 717) static inline bool __is_eff(kuid_t uid, struct cred *cred)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 718) { return uid_eq(cred->euid, uid); }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 719)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 720) static inline bool __is_suid(kuid_t uid, struct cred *cred)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 721) { return !__is_real(uid, cred) && __is_eff(uid, cred); }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 722)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 723) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 724) * handle_privileged_root - Handle case of privileged root
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 725) * @bprm: The execution parameters, including the proposed creds
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 726) * @has_fcap: Are any file capabilities set?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 727) * @effective: Do we have effective root privilege?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 728) * @root_uid: This namespace' root UID WRT initial USER namespace
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 729) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 730) * Handle the case where root is privileged and hasn't been neutered by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 731) * SECURE_NOROOT. If file capabilities are set, they won't be combined with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 732) * set UID root and nothing is changed. If we are root, cap_permitted is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 733) * updated. If we have become set UID root, the effective bit is set.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 734) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 735) static void handle_privileged_root(struct linux_binprm *bprm, bool has_fcap,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 736) bool *effective, kuid_t root_uid)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 737) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 738) const struct cred *old = current_cred();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 739) struct cred *new = bprm->cred;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 740)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 741) if (!root_privileged())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 742) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 743) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 744) * If the legacy file capability is set, then don't set privs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 745) * for a setuid root binary run by a non-root user. Do set it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 746) * for a root user just to cause least surprise to an admin.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 747) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 748) if (has_fcap && __is_suid(root_uid, new)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 749) warn_setuid_and_fcaps_mixed(bprm->filename);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 750) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 751) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 752) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 753) * To support inheritance of root-permissions and suid-root
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 754) * executables under compatibility mode, we override the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 755) * capability sets for the file.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 756) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 757) if (__is_eff(root_uid, new) || __is_real(root_uid, new)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 758) /* pP' = (cap_bset & ~0) | (pI & ~0) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 759) new->cap_permitted = cap_combine(old->cap_bset,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 760) old->cap_inheritable);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 761) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 762) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 763) * If only the real uid is 0, we do not set the effective bit.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 764) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 765) if (__is_eff(root_uid, new))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 766) *effective = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 767) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 768)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 769) #define __cap_gained(field, target, source) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 770) !cap_issubset(target->cap_##field, source->cap_##field)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 771) #define __cap_grew(target, source, cred) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 772) !cap_issubset(cred->cap_##target, cred->cap_##source)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 773) #define __cap_full(field, cred) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 774) cap_issubset(CAP_FULL_SET, cred->cap_##field)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 775)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 776) static inline bool __is_setuid(struct cred *new, const struct cred *old)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 777) { return !uid_eq(new->euid, old->uid); }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 778)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 779) static inline bool __is_setgid(struct cred *new, const struct cred *old)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 780) { return !gid_eq(new->egid, old->gid); }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 781)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 782) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 783) * 1) Audit candidate if current->cap_effective is set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 784) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 785) * We do not bother to audit if 3 things are true:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 786) * 1) cap_effective has all caps
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 787) * 2) we became root *OR* are were already root
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 788) * 3) root is supposed to have all caps (SECURE_NOROOT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 789) * Since this is just a normal root execing a process.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 790) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 791) * Number 1 above might fail if you don't have a full bset, but I think
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 792) * that is interesting information to audit.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 793) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 794) * A number of other conditions require logging:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 795) * 2) something prevented setuid root getting all caps
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 796) * 3) non-setuid root gets fcaps
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 797) * 4) non-setuid root gets ambient
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 798) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 799) static inline bool nonroot_raised_pE(struct cred *new, const struct cred *old,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 800) kuid_t root, bool has_fcap)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 801) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 802) bool ret = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 803)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 804) if ((__cap_grew(effective, ambient, new) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 805) !(__cap_full(effective, new) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 806) (__is_eff(root, new) || __is_real(root, new)) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 807) root_privileged())) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 808) (root_privileged() &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 809) __is_suid(root, new) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 810) !__cap_full(effective, new)) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 811) (!__is_setuid(new, old) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 812) ((has_fcap &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 813) __cap_gained(permitted, new, old)) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 814) __cap_gained(ambient, new, old))))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 815)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 816) ret = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 817)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 818) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 819) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 820)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 821) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 822) * cap_bprm_creds_from_file - Set up the proposed credentials for execve().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 823) * @bprm: The execution parameters, including the proposed creds
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 824) * @file: The file to pull the credentials from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 825) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 826) * Set up the proposed credentials for a new execution context being
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 827) * constructed by execve(). The proposed creds in @bprm->cred is altered,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 828) * which won't take effect immediately. Returns 0 if successful, -ve on error.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 829) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 830) int cap_bprm_creds_from_file(struct linux_binprm *bprm, struct file *file)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 831) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 832) /* Process setpcap binaries and capabilities for uid 0 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 833) const struct cred *old = current_cred();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 834) struct cred *new = bprm->cred;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 835) bool effective = false, has_fcap = false, is_setid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 836) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 837) kuid_t root_uid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 838)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 839) if (WARN_ON(!cap_ambient_invariant_ok(old)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 840) return -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 841)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 842) ret = get_file_caps(bprm, file, &effective, &has_fcap);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 843) if (ret < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 844) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 845)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 846) root_uid = make_kuid(new->user_ns, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 847)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 848) handle_privileged_root(bprm, has_fcap, &effective, root_uid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 849)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 850) /* if we have fs caps, clear dangerous personality flags */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 851) if (__cap_gained(permitted, new, old))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 852) bprm->per_clear |= PER_CLEAR_ON_SETID;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 853)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 854) /* Don't let someone trace a set[ug]id/setpcap binary with the revised
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 855) * credentials unless they have the appropriate permit.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 856) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 857) * In addition, if NO_NEW_PRIVS, then ensure we get no new privs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 858) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 859) is_setid = __is_setuid(new, old) || __is_setgid(new, old);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 860)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 861) if ((is_setid || __cap_gained(permitted, new, old)) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 862) ((bprm->unsafe & ~LSM_UNSAFE_PTRACE) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 863) !ptracer_capable(current, new->user_ns))) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 864) /* downgrade; they get no more than they had, and maybe less */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 865) if (!ns_capable(new->user_ns, CAP_SETUID) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 866) (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 867) new->euid = new->uid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 868) new->egid = new->gid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 869) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 870) new->cap_permitted = cap_intersect(new->cap_permitted,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 871) old->cap_permitted);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 872) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 873)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 874) new->suid = new->fsuid = new->euid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 875) new->sgid = new->fsgid = new->egid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 876)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 877) /* File caps or setid cancels ambient. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 878) if (has_fcap || is_setid)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 879) cap_clear(new->cap_ambient);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 880)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 881) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 882) * Now that we've computed pA', update pP' to give:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 883) * pP' = (X & fP) | (pI & fI) | pA'
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 884) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 885) new->cap_permitted = cap_combine(new->cap_permitted, new->cap_ambient);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 886)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 887) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 888) * Set pE' = (fE ? pP' : pA'). Because pA' is zero if fE is set,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 889) * this is the same as pE' = (fE ? pP' : 0) | pA'.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 890) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 891) if (effective)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 892) new->cap_effective = new->cap_permitted;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 893) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 894) new->cap_effective = new->cap_ambient;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 895)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 896) if (WARN_ON(!cap_ambient_invariant_ok(new)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 897) return -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 898)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 899) if (nonroot_raised_pE(new, old, root_uid, has_fcap)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 900) ret = audit_log_bprm_fcaps(bprm, new, old);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 901) if (ret < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 902) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 903) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 904)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 905) new->securebits &= ~issecure_mask(SECURE_KEEP_CAPS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 906)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 907) if (WARN_ON(!cap_ambient_invariant_ok(new)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 908) return -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 909)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 910) /* Check for privilege-elevated exec. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 911) if (is_setid ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 912) (!__is_real(root_uid, new) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 913) (effective ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 914) __cap_grew(permitted, ambient, new))))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 915) bprm->secureexec = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 916)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 917) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 918) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 919)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 920) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 921) * cap_inode_setxattr - Determine whether an xattr may be altered
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 922) * @dentry: The inode/dentry being altered
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 923) * @name: The name of the xattr to be changed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 924) * @value: The value that the xattr will be changed to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 925) * @size: The size of value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 926) * @flags: The replacement flag
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 927) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 928) * Determine whether an xattr may be altered or set on an inode, returning 0 if
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 929) * permission is granted, -ve if denied.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 930) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 931) * This is used to make sure security xattrs don't get updated or set by those
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 932) * who aren't privileged to do so.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 933) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 934) int cap_inode_setxattr(struct dentry *dentry, const char *name,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 935) const void *value, size_t size, int flags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 936) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 937) struct user_namespace *user_ns = dentry->d_sb->s_user_ns;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 938)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 939) /* Ignore non-security xattrs */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 940) if (strncmp(name, XATTR_SECURITY_PREFIX,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 941) XATTR_SECURITY_PREFIX_LEN) != 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 942) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 943)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 944) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 945) * For XATTR_NAME_CAPS the check will be done in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 946) * cap_convert_nscap(), called by setxattr()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 947) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 948) if (strcmp(name, XATTR_NAME_CAPS) == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 949) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 950)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 951) if (!ns_capable(user_ns, CAP_SYS_ADMIN))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 952) return -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 953) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 954) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 955)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 956) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 957) * cap_inode_removexattr - Determine whether an xattr may be removed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 958) * @dentry: The inode/dentry being altered
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 959) * @name: The name of the xattr to be changed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 960) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 961) * Determine whether an xattr may be removed from an inode, returning 0 if
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 962) * permission is granted, -ve if denied.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 963) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 964) * This is used to make sure security xattrs don't get removed by those who
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 965) * aren't privileged to remove them.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 966) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 967) int cap_inode_removexattr(struct dentry *dentry, const char *name)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 968) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 969) struct user_namespace *user_ns = dentry->d_sb->s_user_ns;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 970)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 971) /* Ignore non-security xattrs */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 972) if (strncmp(name, XATTR_SECURITY_PREFIX,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 973) XATTR_SECURITY_PREFIX_LEN) != 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 974) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 975)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 976) if (strcmp(name, XATTR_NAME_CAPS) == 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 977) /* security.capability gets namespaced */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 978) struct inode *inode = d_backing_inode(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 979) if (!inode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 980) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 981) if (!capable_wrt_inode_uidgid(inode, CAP_SETFCAP))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 982) return -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 983) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 984) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 985)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 986) if (!ns_capable(user_ns, CAP_SYS_ADMIN))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 987) return -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 988) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 989) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 990)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 991) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 992) * cap_emulate_setxuid() fixes the effective / permitted capabilities of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 993) * a process after a call to setuid, setreuid, or setresuid.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 994) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 995) * 1) When set*uiding _from_ one of {r,e,s}uid == 0 _to_ all of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 996) * {r,e,s}uid != 0, the permitted and effective capabilities are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 997) * cleared.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 998) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 999) * 2) When set*uiding _from_ euid == 0 _to_ euid != 0, the effective
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1000) * capabilities of the process are cleared.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1001) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1002) * 3) When set*uiding _from_ euid != 0 _to_ euid == 0, the effective
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1003) * capabilities are set to the permitted capabilities.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1004) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1005) * fsuid is handled elsewhere. fsuid == 0 and {r,e,s}uid!= 0 should
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1006) * never happen.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1007) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1008) * -astor
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1009) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1010) * cevans - New behaviour, Oct '99
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1011) * A process may, via prctl(), elect to keep its capabilities when it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1012) * calls setuid() and switches away from uid==0. Both permitted and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1013) * effective sets will be retained.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1014) * Without this change, it was impossible for a daemon to drop only some
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1015) * of its privilege. The call to setuid(!=0) would drop all privileges!
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1016) * Keeping uid 0 is not an option because uid 0 owns too many vital
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1017) * files..
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1018) * Thanks to Olaf Kirch and Peter Benie for spotting this.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1019) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1020) static inline void cap_emulate_setxuid(struct cred *new, const struct cred *old)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1021) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1022) kuid_t root_uid = make_kuid(old->user_ns, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1023)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1024) if ((uid_eq(old->uid, root_uid) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1025) uid_eq(old->euid, root_uid) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1026) uid_eq(old->suid, root_uid)) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1027) (!uid_eq(new->uid, root_uid) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1028) !uid_eq(new->euid, root_uid) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1029) !uid_eq(new->suid, root_uid))) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1030) if (!issecure(SECURE_KEEP_CAPS)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1031) cap_clear(new->cap_permitted);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1032) cap_clear(new->cap_effective);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1033) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1034)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1035) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1036) * Pre-ambient programs expect setresuid to nonroot followed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1037) * by exec to drop capabilities. We should make sure that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1038) * this remains the case.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1039) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1040) cap_clear(new->cap_ambient);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1041) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1042) if (uid_eq(old->euid, root_uid) && !uid_eq(new->euid, root_uid))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1043) cap_clear(new->cap_effective);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1044) if (!uid_eq(old->euid, root_uid) && uid_eq(new->euid, root_uid))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1045) new->cap_effective = new->cap_permitted;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1046) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1047)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1048) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1049) * cap_task_fix_setuid - Fix up the results of setuid() call
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1050) * @new: The proposed credentials
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1051) * @old: The current task's current credentials
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1052) * @flags: Indications of what has changed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1053) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1054) * Fix up the results of setuid() call before the credential changes are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1055) * actually applied, returning 0 to grant the changes, -ve to deny them.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1056) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1057) int cap_task_fix_setuid(struct cred *new, const struct cred *old, int flags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1058) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1059) switch (flags) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1060) case LSM_SETID_RE:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1061) case LSM_SETID_ID:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1062) case LSM_SETID_RES:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1063) /* juggle the capabilities to follow [RES]UID changes unless
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1064) * otherwise suppressed */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1065) if (!issecure(SECURE_NO_SETUID_FIXUP))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1066) cap_emulate_setxuid(new, old);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1067) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1068)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1069) case LSM_SETID_FS:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1070) /* juggle the capabilties to follow FSUID changes, unless
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1071) * otherwise suppressed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1072) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1073) * FIXME - is fsuser used for all CAP_FS_MASK capabilities?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1074) * if not, we might be a bit too harsh here.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1075) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1076) if (!issecure(SECURE_NO_SETUID_FIXUP)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1077) kuid_t root_uid = make_kuid(old->user_ns, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1078) if (uid_eq(old->fsuid, root_uid) && !uid_eq(new->fsuid, root_uid))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1079) new->cap_effective =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1080) cap_drop_fs_set(new->cap_effective);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1081)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1082) if (!uid_eq(old->fsuid, root_uid) && uid_eq(new->fsuid, root_uid))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1083) new->cap_effective =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1084) cap_raise_fs_set(new->cap_effective,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1085) new->cap_permitted);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1086) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1087) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1088)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1089) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1090) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1091) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1092)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1093) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1094) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1095)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1096) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1097) * Rationale: code calling task_setscheduler, task_setioprio, and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1098) * task_setnice, assumes that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1099) * . if capable(cap_sys_nice), then those actions should be allowed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1100) * . if not capable(cap_sys_nice), but acting on your own processes,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1101) * then those actions should be allowed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1102) * This is insufficient now since you can call code without suid, but
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1103) * yet with increased caps.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1104) * So we check for increased caps on the target process.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1105) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1106) static int cap_safe_nice(struct task_struct *p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1107) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1108) int is_subset, ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1109)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1110) rcu_read_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1111) is_subset = cap_issubset(__task_cred(p)->cap_permitted,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1112) current_cred()->cap_permitted);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1113) if (!is_subset && !ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1114) ret = -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1115) rcu_read_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1116)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1117) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1118) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1119)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1120) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1121) * cap_task_setscheduler - Detemine if scheduler policy change is permitted
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1122) * @p: The task to affect
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1123) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1124) * Detemine if the requested scheduler policy change is permitted for the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1125) * specified task, returning 0 if permission is granted, -ve if denied.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1126) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1127) int cap_task_setscheduler(struct task_struct *p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1128) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1129) return cap_safe_nice(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1130) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1131)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1132) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1133) * cap_task_ioprio - Detemine if I/O priority change is permitted
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1134) * @p: The task to affect
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1135) * @ioprio: The I/O priority to set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1136) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1137) * Detemine if the requested I/O priority change is permitted for the specified
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1138) * task, returning 0 if permission is granted, -ve if denied.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1139) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1140) int cap_task_setioprio(struct task_struct *p, int ioprio)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1141) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1142) return cap_safe_nice(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1143) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1144)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1145) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1146) * cap_task_ioprio - Detemine if task priority change is permitted
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1147) * @p: The task to affect
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1148) * @nice: The nice value to set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1149) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1150) * Detemine if the requested task priority change is permitted for the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1151) * specified task, returning 0 if permission is granted, -ve if denied.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1152) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1153) int cap_task_setnice(struct task_struct *p, int nice)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1154) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1155) return cap_safe_nice(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1156) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1157)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1158) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1159) * Implement PR_CAPBSET_DROP. Attempt to remove the specified capability from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1160) * the current task's bounding set. Returns 0 on success, -ve on error.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1161) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1162) static int cap_prctl_drop(unsigned long cap)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1163) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1164) struct cred *new;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1165)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1166) if (!ns_capable(current_user_ns(), CAP_SETPCAP))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1167) return -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1168) if (!cap_valid(cap))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1169) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1170)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1171) new = prepare_creds();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1172) if (!new)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1173) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1174) cap_lower(new->cap_bset, cap);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1175) return commit_creds(new);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1176) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1177)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1178) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1179) * cap_task_prctl - Implement process control functions for this security module
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1180) * @option: The process control function requested
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1181) * @arg2, @arg3, @arg4, @arg5: The argument data for this function
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1182) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1183) * Allow process control functions (sys_prctl()) to alter capabilities; may
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1184) * also deny access to other functions not otherwise implemented here.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1185) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1186) * Returns 0 or +ve on success, -ENOSYS if this function is not implemented
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1187) * here, other -ve on error. If -ENOSYS is returned, sys_prctl() and other LSM
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1188) * modules will consider performing the function.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1189) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1190) int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1191) unsigned long arg4, unsigned long arg5)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1192) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1193) const struct cred *old = current_cred();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1194) struct cred *new;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1195)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1196) switch (option) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1197) case PR_CAPBSET_READ:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1198) if (!cap_valid(arg2))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1199) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1200) return !!cap_raised(old->cap_bset, arg2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1201)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1202) case PR_CAPBSET_DROP:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1203) return cap_prctl_drop(arg2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1204)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1205) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1206) * The next four prctl's remain to assist with transitioning a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1207) * system from legacy UID=0 based privilege (when filesystem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1208) * capabilities are not in use) to a system using filesystem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1209) * capabilities only - as the POSIX.1e draft intended.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1210) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1211) * Note:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1212) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1213) * PR_SET_SECUREBITS =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1214) * issecure_mask(SECURE_KEEP_CAPS_LOCKED)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1215) * | issecure_mask(SECURE_NOROOT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1216) * | issecure_mask(SECURE_NOROOT_LOCKED)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1217) * | issecure_mask(SECURE_NO_SETUID_FIXUP)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1218) * | issecure_mask(SECURE_NO_SETUID_FIXUP_LOCKED)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1219) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1220) * will ensure that the current process and all of its
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1221) * children will be locked into a pure
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1222) * capability-based-privilege environment.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1223) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1224) case PR_SET_SECUREBITS:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1225) if ((((old->securebits & SECURE_ALL_LOCKS) >> 1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1226) & (old->securebits ^ arg2)) /*[1]*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1227) || ((old->securebits & SECURE_ALL_LOCKS & ~arg2)) /*[2]*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1228) || (arg2 & ~(SECURE_ALL_LOCKS | SECURE_ALL_BITS)) /*[3]*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1229) || (cap_capable(current_cred(),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1230) current_cred()->user_ns,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1231) CAP_SETPCAP,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1232) CAP_OPT_NONE) != 0) /*[4]*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1233) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1234) * [1] no changing of bits that are locked
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1235) * [2] no unlocking of locks
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1236) * [3] no setting of unsupported bits
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1237) * [4] doing anything requires privilege (go read about
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1238) * the "sendmail capabilities bug")
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1239) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1240) )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1241) /* cannot change a locked bit */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1242) return -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1243)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1244) new = prepare_creds();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1245) if (!new)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1246) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1247) new->securebits = arg2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1248) return commit_creds(new);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1249)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1250) case PR_GET_SECUREBITS:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1251) return old->securebits;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1252)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1253) case PR_GET_KEEPCAPS:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1254) return !!issecure(SECURE_KEEP_CAPS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1255)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1256) case PR_SET_KEEPCAPS:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1257) if (arg2 > 1) /* Note, we rely on arg2 being unsigned here */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1258) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1259) if (issecure(SECURE_KEEP_CAPS_LOCKED))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1260) return -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1261)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1262) new = prepare_creds();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1263) if (!new)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1264) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1265) if (arg2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1266) new->securebits |= issecure_mask(SECURE_KEEP_CAPS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1267) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1268) new->securebits &= ~issecure_mask(SECURE_KEEP_CAPS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1269) return commit_creds(new);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1270)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1271) case PR_CAP_AMBIENT:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1272) if (arg2 == PR_CAP_AMBIENT_CLEAR_ALL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1273) if (arg3 | arg4 | arg5)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1274) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1275)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1276) new = prepare_creds();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1277) if (!new)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1278) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1279) cap_clear(new->cap_ambient);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1280) return commit_creds(new);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1281) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1282)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1283) if (((!cap_valid(arg3)) | arg4 | arg5))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1284) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1285)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1286) if (arg2 == PR_CAP_AMBIENT_IS_SET) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1287) return !!cap_raised(current_cred()->cap_ambient, arg3);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1288) } else if (arg2 != PR_CAP_AMBIENT_RAISE &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1289) arg2 != PR_CAP_AMBIENT_LOWER) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1290) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1291) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1292) if (arg2 == PR_CAP_AMBIENT_RAISE &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1293) (!cap_raised(current_cred()->cap_permitted, arg3) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1294) !cap_raised(current_cred()->cap_inheritable,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1295) arg3) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1296) issecure(SECURE_NO_CAP_AMBIENT_RAISE)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1297) return -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1298)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1299) new = prepare_creds();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1300) if (!new)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1301) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1302) if (arg2 == PR_CAP_AMBIENT_RAISE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1303) cap_raise(new->cap_ambient, arg3);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1304) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1305) cap_lower(new->cap_ambient, arg3);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1306) return commit_creds(new);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1307) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1308)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1309) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1310) /* No functionality available - continue with default */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1311) return -ENOSYS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1312) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1313) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1314)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1315) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1316) * cap_vm_enough_memory - Determine whether a new virtual mapping is permitted
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1317) * @mm: The VM space in which the new mapping is to be made
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1318) * @pages: The size of the mapping
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1319) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1320) * Determine whether the allocation of a new virtual mapping by the current
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1321) * task is permitted, returning 1 if permission is granted, 0 if not.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1322) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1323) int cap_vm_enough_memory(struct mm_struct *mm, long pages)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1324) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1325) int cap_sys_admin = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1326)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1327) if (cap_capable(current_cred(), &init_user_ns,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1328) CAP_SYS_ADMIN, CAP_OPT_NOAUDIT) == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1329) cap_sys_admin = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1330)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1331) return cap_sys_admin;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1332) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1333)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1334) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1335) * cap_mmap_addr - check if able to map given addr
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1336) * @addr: address attempting to be mapped
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1337) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1338) * If the process is attempting to map memory below dac_mmap_min_addr they need
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1339) * CAP_SYS_RAWIO. The other parameters to this function are unused by the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1340) * capability security module. Returns 0 if this mapping should be allowed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1341) * -EPERM if not.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1342) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1343) int cap_mmap_addr(unsigned long addr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1344) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1345) int ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1346)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1347) if (addr < dac_mmap_min_addr) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1348) ret = cap_capable(current_cred(), &init_user_ns, CAP_SYS_RAWIO,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1349) CAP_OPT_NONE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1350) /* set PF_SUPERPRIV if it turns out we allow the low mmap */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1351) if (ret == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1352) current->flags |= PF_SUPERPRIV;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1353) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1354) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1355) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1356)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1357) int cap_mmap_file(struct file *file, unsigned long reqprot,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1358) unsigned long prot, unsigned long flags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1359) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1360) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1361) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1362)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1363) #ifdef CONFIG_SECURITY
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1364)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1365) static struct security_hook_list capability_hooks[] __lsm_ro_after_init = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1366) LSM_HOOK_INIT(capable, cap_capable),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1367) LSM_HOOK_INIT(settime, cap_settime),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1368) LSM_HOOK_INIT(ptrace_access_check, cap_ptrace_access_check),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1369) LSM_HOOK_INIT(ptrace_traceme, cap_ptrace_traceme),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1370) LSM_HOOK_INIT(capget, cap_capget),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1371) LSM_HOOK_INIT(capset, cap_capset),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1372) LSM_HOOK_INIT(bprm_creds_from_file, cap_bprm_creds_from_file),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1373) LSM_HOOK_INIT(inode_need_killpriv, cap_inode_need_killpriv),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1374) LSM_HOOK_INIT(inode_killpriv, cap_inode_killpriv),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1375) LSM_HOOK_INIT(inode_getsecurity, cap_inode_getsecurity),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1376) LSM_HOOK_INIT(mmap_addr, cap_mmap_addr),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1377) LSM_HOOK_INIT(mmap_file, cap_mmap_file),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1378) LSM_HOOK_INIT(task_fix_setuid, cap_task_fix_setuid),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1379) LSM_HOOK_INIT(task_prctl, cap_task_prctl),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1380) LSM_HOOK_INIT(task_setscheduler, cap_task_setscheduler),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1381) LSM_HOOK_INIT(task_setioprio, cap_task_setioprio),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1382) LSM_HOOK_INIT(task_setnice, cap_task_setnice),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1383) LSM_HOOK_INIT(vm_enough_memory, cap_vm_enough_memory),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1384) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1385)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1386) static int __init capability_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1387) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1388) security_add_hooks(capability_hooks, ARRAY_SIZE(capability_hooks),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1389) "capability");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1390) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1391) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1392)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1393) DEFINE_LSM(capability) = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1394) .name = "capability",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1395) .order = LSM_ORDER_FIRST,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1396) .init = capability_init,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1397) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1398)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1399) #endif /* CONFIG_SECURITY */
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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