^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) #include <linux/fanotify.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) #include <linux/fdtable.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) #include <linux/fsnotify_backend.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) #include <linux/init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) #include <linux/jiffies.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) #include <linux/kernel.h> /* UINT_MAX */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) #include <linux/mount.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include <linux/sched.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <linux/sched/user.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/sched/signal.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/types.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <linux/wait.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <linux/audit.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <linux/sched/mm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include <linux/statfs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include "fanotify.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) static bool fanotify_path_equal(struct path *p1, struct path *p2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) return p1->mnt == p2->mnt && p1->dentry == p2->dentry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) static inline bool fanotify_fsid_equal(__kernel_fsid_t *fsid1,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) __kernel_fsid_t *fsid2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) return fsid1->val[0] == fsid2->val[0] && fsid1->val[1] == fsid2->val[1];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) static bool fanotify_fh_equal(struct fanotify_fh *fh1,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) struct fanotify_fh *fh2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) if (fh1->type != fh2->type || fh1->len != fh2->len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) return !fh1->len ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) !memcmp(fanotify_fh_buf(fh1), fanotify_fh_buf(fh2), fh1->len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) static bool fanotify_fid_event_equal(struct fanotify_fid_event *ffe1,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) struct fanotify_fid_event *ffe2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) /* Do not merge fid events without object fh */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) if (!ffe1->object_fh.len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) return fanotify_fsid_equal(&ffe1->fsid, &ffe2->fsid) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) fanotify_fh_equal(&ffe1->object_fh, &ffe2->object_fh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) static bool fanotify_info_equal(struct fanotify_info *info1,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) struct fanotify_info *info2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) if (info1->dir_fh_totlen != info2->dir_fh_totlen ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) info1->file_fh_totlen != info2->file_fh_totlen ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) info1->name_len != info2->name_len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) if (info1->dir_fh_totlen &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) !fanotify_fh_equal(fanotify_info_dir_fh(info1),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) fanotify_info_dir_fh(info2)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) if (info1->file_fh_totlen &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) !fanotify_fh_equal(fanotify_info_file_fh(info1),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) fanotify_info_file_fh(info2)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) return !info1->name_len ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) !memcmp(fanotify_info_name(info1), fanotify_info_name(info2),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) info1->name_len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) static bool fanotify_name_event_equal(struct fanotify_name_event *fne1,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) struct fanotify_name_event *fne2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) struct fanotify_info *info1 = &fne1->info;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) struct fanotify_info *info2 = &fne2->info;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) /* Do not merge name events without dir fh */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) if (!info1->dir_fh_totlen)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) if (!fanotify_fsid_equal(&fne1->fsid, &fne2->fsid))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) return fanotify_info_equal(info1, info2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) static bool fanotify_should_merge(struct fsnotify_event *old_fsn,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) struct fsnotify_event *new_fsn)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) struct fanotify_event *old, *new;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) pr_debug("%s: old=%p new=%p\n", __func__, old_fsn, new_fsn);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) old = FANOTIFY_E(old_fsn);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) new = FANOTIFY_E(new_fsn);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) if (old_fsn->objectid != new_fsn->objectid ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) old->type != new->type || old->pid != new->pid)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) * We want to merge many dirent events in the same dir (i.e.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) * creates/unlinks/renames), but we do not want to merge dirent
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) * events referring to subdirs with dirent events referring to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) * non subdirs, otherwise, user won't be able to tell from a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) * mask FAN_CREATE|FAN_DELETE|FAN_ONDIR if it describes mkdir+
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) * unlink pair or rmdir+create pair of events.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) if ((old->mask & FS_ISDIR) != (new->mask & FS_ISDIR))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) switch (old->type) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) case FANOTIFY_EVENT_TYPE_PATH:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) return fanotify_path_equal(fanotify_event_path(old),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) fanotify_event_path(new));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) case FANOTIFY_EVENT_TYPE_FID:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) return fanotify_fid_event_equal(FANOTIFY_FE(old),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) FANOTIFY_FE(new));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) case FANOTIFY_EVENT_TYPE_FID_NAME:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) return fanotify_name_event_equal(FANOTIFY_NE(old),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) FANOTIFY_NE(new));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) WARN_ON_ONCE(1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) /* Limit event merges to limit CPU overhead per event */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) #define FANOTIFY_MAX_MERGE_EVENTS 128
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) /* and the list better be locked by something too! */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) static int fanotify_merge(struct list_head *list, struct fsnotify_event *event)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) struct fsnotify_event *test_event;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) struct fanotify_event *new;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) int i = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) pr_debug("%s: list=%p event=%p\n", __func__, list, event);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) new = FANOTIFY_E(event);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) * Don't merge a permission event with any other event so that we know
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) * the event structure we have created in fanotify_handle_event() is the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) * one we should check for permission response.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) if (fanotify_is_perm_event(new->mask))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) list_for_each_entry_reverse(test_event, list, list) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) if (++i > FANOTIFY_MAX_MERGE_EVENTS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) if (fanotify_should_merge(test_event, event)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) FANOTIFY_E(test_event)->mask |= new->mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) * Wait for response to permission event. The function also takes care of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) * freeing the permission event (or offloads that in case the wait is canceled
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) * by a signal). The function returns 0 in case access got allowed by userspace,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) * -EPERM in case userspace disallowed the access, and -ERESTARTSYS in case
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) * the wait got interrupted by a signal.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) static int fanotify_get_response(struct fsnotify_group *group,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) struct fanotify_perm_event *event,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) struct fsnotify_iter_info *iter_info)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) pr_debug("%s: group=%p event=%p\n", __func__, group, event);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) ret = wait_event_killable(group->fanotify_data.access_waitq,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) event->state == FAN_EVENT_ANSWERED);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) /* Signal pending? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) if (ret < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) spin_lock(&group->notification_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) /* Event reported to userspace and no answer yet? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) if (event->state == FAN_EVENT_REPORTED) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) /* Event will get freed once userspace answers to it */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) event->state = FAN_EVENT_CANCELED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) spin_unlock(&group->notification_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) /* Event not yet reported? Just remove it. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) if (event->state == FAN_EVENT_INIT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) fsnotify_remove_queued_event(group, &event->fae.fse);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) * Event may be also answered in case signal delivery raced
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) * with wakeup. In that case we have nothing to do besides
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) * freeing the event and reporting error.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) spin_unlock(&group->notification_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) /* userspace responded, convert to something usable */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) switch (event->response & ~FAN_AUDIT) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) case FAN_ALLOW:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) case FAN_DENY:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) ret = -EPERM;
^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) /* Check if the response should be audited */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) if (event->response & FAN_AUDIT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) audit_fanotify(event->response & ~FAN_AUDIT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) pr_debug("%s: group=%p event=%p about to return ret=%d\n", __func__,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) group, event, ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) fsnotify_destroy_event(group, &event->fae.fse);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) * This function returns a mask for an event that only contains the flags
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) * that have been specifically requested by the user. Flags that may have
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) * been included within the event mask, but have not been explicitly
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) * requested by the user, will not be present in the returned mask.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) static u32 fanotify_group_event_mask(struct fsnotify_group *group,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) struct fsnotify_iter_info *iter_info,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) u32 event_mask, const void *data,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) int data_type, struct inode *dir)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) __u32 marks_mask = 0, marks_ignored_mask = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) __u32 test_mask, user_mask = FANOTIFY_OUTGOING_EVENTS |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) FANOTIFY_EVENT_FLAGS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) const struct path *path = fsnotify_data_path(data, data_type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) unsigned int fid_mode = FAN_GROUP_FLAG(group, FANOTIFY_FID_BITS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) struct fsnotify_mark *mark;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) int type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) pr_debug("%s: report_mask=%x mask=%x data=%p data_type=%d\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) __func__, iter_info->report_mask, event_mask, data, data_type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) if (!fid_mode) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) /* Do we have path to open a file descriptor? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) if (!path)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) /* Path type events are only relevant for files and dirs */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) if (!d_is_reg(path->dentry) && !d_can_lookup(path->dentry))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) } else if (!(fid_mode & FAN_REPORT_FID)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) /* Do we have a directory inode to report? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) if (!dir && !(event_mask & FS_ISDIR))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) fsnotify_foreach_obj_type(type) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) if (!fsnotify_iter_should_report_type(iter_info, type))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) mark = iter_info->marks[type];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) /* Apply ignore mask regardless of ISDIR and ON_CHILD flags */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) marks_ignored_mask |= mark->ignored_mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) * If the event is on dir and this mark doesn't care about
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) * events on dir, don't send it!
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) if (event_mask & FS_ISDIR && !(mark->mask & FS_ISDIR))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) * If the event is on a child and this mark is on a parent not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) * watching children, don't send it!
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) if (type == FSNOTIFY_OBJ_TYPE_PARENT &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) !(mark->mask & FS_EVENT_ON_CHILD))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) marks_mask |= mark->mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) test_mask = event_mask & marks_mask & ~marks_ignored_mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) * For dirent modification events (create/delete/move) that do not carry
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) * the child entry name information, we report FAN_ONDIR for mkdir/rmdir
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) * so user can differentiate them from creat/unlink.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) * For backward compatibility and consistency, do not report FAN_ONDIR
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) * to user in legacy fanotify mode (reporting fd) and report FAN_ONDIR
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) * to user in fid mode for all event types.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) * We never report FAN_EVENT_ON_CHILD to user, but we do pass it in to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) * fanotify_alloc_event() when group is reporting fid as indication
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) * that event happened on child.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) if (fid_mode) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) /* Do not report event flags without any event */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) if (!(test_mask & ~FANOTIFY_EVENT_FLAGS))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) user_mask &= ~FANOTIFY_EVENT_FLAGS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) return test_mask & user_mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) * Check size needed to encode fanotify_fh.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) * Return size of encoded fh without fanotify_fh header.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) * Return 0 on failure to encode.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) static int fanotify_encode_fh_len(struct inode *inode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) int dwords = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) if (!inode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) exportfs_encode_inode_fh(inode, NULL, &dwords, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) return dwords << 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) * Encode fanotify_fh.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) * Return total size of encoded fh including fanotify_fh header.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) * Return 0 on failure to encode.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) static int fanotify_encode_fh(struct fanotify_fh *fh, struct inode *inode,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) unsigned int fh_len, gfp_t gfp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) int dwords, type = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) char *ext_buf = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) void *buf = fh->buf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) fh->type = FILEID_ROOT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) fh->len = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) fh->flags = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) if (!inode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) return 0;
^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) * !gpf means preallocated variable size fh, but fh_len could
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) * be zero in that case if encoding fh len failed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) err = -ENOENT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) if (fh_len < 4 || WARN_ON_ONCE(fh_len % 4))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) goto out_err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) /* No external buffer in a variable size allocated fh */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) if (gfp && fh_len > FANOTIFY_INLINE_FH_LEN) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) /* Treat failure to allocate fh as failure to encode fh */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) err = -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) ext_buf = kmalloc(fh_len, gfp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) if (!ext_buf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) goto out_err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) *fanotify_fh_ext_buf_ptr(fh) = ext_buf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) buf = ext_buf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) fh->flags |= FANOTIFY_FH_FLAG_EXT_BUF;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) dwords = fh_len >> 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) type = exportfs_encode_inode_fh(inode, buf, &dwords, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) err = -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) if (!type || type == FILEID_INVALID || fh_len != dwords << 2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) goto out_err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) fh->type = type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) fh->len = fh_len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) return FANOTIFY_FH_HDR_LEN + fh_len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) out_err:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) pr_warn_ratelimited("fanotify: failed to encode fid (type=%d, len=%d, err=%i)\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) type, fh_len, err);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) kfree(ext_buf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) *fanotify_fh_ext_buf_ptr(fh) = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) /* Report the event without a file identifier on encode error */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) fh->type = FILEID_INVALID;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) fh->len = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) * The inode to use as identifier when reporting fid depends on the event.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) * Report the modified directory inode on dirent modification events.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) * Report the "victim" inode otherwise.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) * For example:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) * FS_ATTRIB reports the child inode even if reported on a watched parent.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) * FS_CREATE reports the modified dir inode and not the created inode.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) static struct inode *fanotify_fid_inode(u32 event_mask, const void *data,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) int data_type, struct inode *dir)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) if (event_mask & ALL_FSNOTIFY_DIRENT_EVENTS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) return dir;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) return fsnotify_data_inode(data, data_type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) * The inode to use as identifier when reporting dir fid depends on the event.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) * Report the modified directory inode on dirent modification events.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) * Report the "victim" inode if "victim" is a directory.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) * Report the parent inode if "victim" is not a directory and event is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416) * reported to parent.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) * Otherwise, do not report dir fid.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) static struct inode *fanotify_dfid_inode(u32 event_mask, const void *data,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) int data_type, struct inode *dir)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) struct inode *inode = fsnotify_data_inode(data, data_type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424) if (event_mask & ALL_FSNOTIFY_DIRENT_EVENTS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425) return dir;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427) if (S_ISDIR(inode->i_mode))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428) return inode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430) return dir;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433) static struct fanotify_event *fanotify_alloc_path_event(const struct path *path,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434) gfp_t gfp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) struct fanotify_path_event *pevent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438) pevent = kmem_cache_alloc(fanotify_path_event_cachep, gfp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439) if (!pevent)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442) pevent->fae.type = FANOTIFY_EVENT_TYPE_PATH;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443) pevent->path = *path;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) path_get(path);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446) return &pevent->fae;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449) static struct fanotify_event *fanotify_alloc_perm_event(const struct path *path,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450) gfp_t gfp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452) struct fanotify_perm_event *pevent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454) pevent = kmem_cache_alloc(fanotify_perm_event_cachep, gfp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455) if (!pevent)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458) pevent->fae.type = FANOTIFY_EVENT_TYPE_PATH_PERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459) pevent->response = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460) pevent->state = FAN_EVENT_INIT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461) pevent->path = *path;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462) path_get(path);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) return &pevent->fae;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467) static struct fanotify_event *fanotify_alloc_fid_event(struct inode *id,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468) __kernel_fsid_t *fsid,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469) gfp_t gfp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 470) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 471) struct fanotify_fid_event *ffe;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 472)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 473) ffe = kmem_cache_alloc(fanotify_fid_event_cachep, gfp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 474) if (!ffe)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 475) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 476)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 477) ffe->fae.type = FANOTIFY_EVENT_TYPE_FID;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 478) ffe->fsid = *fsid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 479) fanotify_encode_fh(&ffe->object_fh, id, fanotify_encode_fh_len(id),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 480) gfp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 481)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 482) return &ffe->fae;
^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 struct fanotify_event *fanotify_alloc_name_event(struct inode *id,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 486) __kernel_fsid_t *fsid,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 487) const struct qstr *file_name,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 488) struct inode *child,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 489) gfp_t gfp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 490) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 491) struct fanotify_name_event *fne;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 492) struct fanotify_info *info;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 493) struct fanotify_fh *dfh, *ffh;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 494) unsigned int dir_fh_len = fanotify_encode_fh_len(id);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 495) unsigned int child_fh_len = fanotify_encode_fh_len(child);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 496) unsigned int size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 497)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 498) size = sizeof(*fne) + FANOTIFY_FH_HDR_LEN + dir_fh_len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 499) if (child_fh_len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 500) size += FANOTIFY_FH_HDR_LEN + child_fh_len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 501) if (file_name)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 502) size += file_name->len + 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 503) fne = kmalloc(size, gfp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 504) if (!fne)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 505) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 506)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 507) fne->fae.type = FANOTIFY_EVENT_TYPE_FID_NAME;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 508) fne->fsid = *fsid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 509) info = &fne->info;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 510) fanotify_info_init(info);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 511) dfh = fanotify_info_dir_fh(info);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 512) info->dir_fh_totlen = fanotify_encode_fh(dfh, id, dir_fh_len, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 513) if (child_fh_len) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 514) ffh = fanotify_info_file_fh(info);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 515) info->file_fh_totlen = fanotify_encode_fh(ffh, child, child_fh_len, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 516) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 517) if (file_name)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 518) fanotify_info_copy_name(info, file_name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 519)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 520) pr_debug("%s: ino=%lu size=%u dir_fh_len=%u child_fh_len=%u name_len=%u name='%.*s'\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 521) __func__, id->i_ino, size, dir_fh_len, child_fh_len,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 522) info->name_len, info->name_len, fanotify_info_name(info));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 523)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 524) return &fne->fae;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 525) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 526)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 527) static struct fanotify_event *fanotify_alloc_event(struct fsnotify_group *group,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 528) u32 mask, const void *data,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 529) int data_type, struct inode *dir,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 530) const struct qstr *file_name,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 531) __kernel_fsid_t *fsid)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 532) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 533) struct fanotify_event *event = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 534) gfp_t gfp = GFP_KERNEL_ACCOUNT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 535) struct inode *id = fanotify_fid_inode(mask, data, data_type, dir);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 536) struct inode *dirid = fanotify_dfid_inode(mask, data, data_type, dir);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 537) const struct path *path = fsnotify_data_path(data, data_type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 538) unsigned int fid_mode = FAN_GROUP_FLAG(group, FANOTIFY_FID_BITS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 539) struct mem_cgroup *old_memcg;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 540) struct inode *child = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 541) bool name_event = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 542)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 543) if ((fid_mode & FAN_REPORT_DIR_FID) && dirid) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 544) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 545) * With both flags FAN_REPORT_DIR_FID and FAN_REPORT_FID, we
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 546) * report the child fid for events reported on a non-dir child
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 547) * in addition to reporting the parent fid and maybe child name.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 548) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 549) if ((fid_mode & FAN_REPORT_FID) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 550) id != dirid && !(mask & FAN_ONDIR))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 551) child = id;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 552)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 553) id = dirid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 554)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 555) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 556) * We record file name only in a group with FAN_REPORT_NAME
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 557) * and when we have a directory inode to report.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 558) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 559) * For directory entry modification event, we record the fid of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 560) * the directory and the name of the modified entry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 561) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 562) * For event on non-directory that is reported to parent, we
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 563) * record the fid of the parent and the name of the child.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 564) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 565) * Even if not reporting name, we need a variable length
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 566) * fanotify_name_event if reporting both parent and child fids.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 567) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 568) if (!(fid_mode & FAN_REPORT_NAME)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 569) name_event = !!child;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 570) file_name = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 571) } else if ((mask & ALL_FSNOTIFY_DIRENT_EVENTS) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 572) !(mask & FAN_ONDIR)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 573) name_event = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 574) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 575) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 576)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 577) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 578) * For queues with unlimited length lost events are not expected and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 579) * can possibly have security implications. Avoid losing events when
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 580) * memory is short. For the limited size queues, avoid OOM killer in the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 581) * target monitoring memcg as it may have security repercussion.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 582) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 583) if (group->max_events == UINT_MAX)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 584) gfp |= __GFP_NOFAIL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 585) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 586) gfp |= __GFP_RETRY_MAYFAIL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 587)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 588) /* Whoever is interested in the event, pays for the allocation. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 589) old_memcg = set_active_memcg(group->memcg);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 590)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 591) if (fanotify_is_perm_event(mask)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 592) event = fanotify_alloc_perm_event(path, gfp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 593) } else if (name_event && (file_name || child)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 594) event = fanotify_alloc_name_event(id, fsid, file_name, child,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 595) gfp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 596) } else if (fid_mode) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 597) event = fanotify_alloc_fid_event(id, fsid, gfp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 598) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 599) event = fanotify_alloc_path_event(path, gfp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 600) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 601)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 602) if (!event)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 603) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 604)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 605) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 606) * Use the victim inode instead of the watching inode as the id for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 607) * event queue, so event reported on parent is merged with event
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 608) * reported on child when both directory and child watches exist.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 609) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 610) fanotify_init_event(event, (unsigned long)id, mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 611) if (FAN_GROUP_FLAG(group, FAN_REPORT_TID))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 612) event->pid = get_pid(task_pid(current));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 613) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 614) event->pid = get_pid(task_tgid(current));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 615)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 616) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 617) set_active_memcg(old_memcg);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 618) return event;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 619) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 620)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 621) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 622) * Get cached fsid of the filesystem containing the object from any connector.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 623) * All connectors are supposed to have the same fsid, but we do not verify that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 624) * here.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 625) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 626) static __kernel_fsid_t fanotify_get_fsid(struct fsnotify_iter_info *iter_info)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 627) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 628) int type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 629) __kernel_fsid_t fsid = {};
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 630)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 631) fsnotify_foreach_obj_type(type) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 632) struct fsnotify_mark_connector *conn;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 633)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 634) if (!fsnotify_iter_should_report_type(iter_info, type))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 635) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 636)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 637) conn = READ_ONCE(iter_info->marks[type]->connector);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 638) /* Mark is just getting destroyed or created? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 639) if (!conn)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 640) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 641) if (!(conn->flags & FSNOTIFY_CONN_FLAG_HAS_FSID))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 642) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 643) /* Pairs with smp_wmb() in fsnotify_add_mark_list() */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 644) smp_rmb();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 645) fsid = conn->fsid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 646) if (WARN_ON_ONCE(!fsid.val[0] && !fsid.val[1]))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 647) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 648) return fsid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 649) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 650)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 651) return fsid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 652) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 653)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 654) static int fanotify_handle_event(struct fsnotify_group *group, u32 mask,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 655) const void *data, int data_type,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 656) struct inode *dir,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 657) const struct qstr *file_name, u32 cookie,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 658) struct fsnotify_iter_info *iter_info)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 659) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 660) int ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 661) struct fanotify_event *event;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 662) struct fsnotify_event *fsn_event;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 663) __kernel_fsid_t fsid = {};
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 664)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 665) BUILD_BUG_ON(FAN_ACCESS != FS_ACCESS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 666) BUILD_BUG_ON(FAN_MODIFY != FS_MODIFY);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 667) BUILD_BUG_ON(FAN_ATTRIB != FS_ATTRIB);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 668) BUILD_BUG_ON(FAN_CLOSE_NOWRITE != FS_CLOSE_NOWRITE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 669) BUILD_BUG_ON(FAN_CLOSE_WRITE != FS_CLOSE_WRITE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 670) BUILD_BUG_ON(FAN_OPEN != FS_OPEN);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 671) BUILD_BUG_ON(FAN_MOVED_TO != FS_MOVED_TO);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 672) BUILD_BUG_ON(FAN_MOVED_FROM != FS_MOVED_FROM);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 673) BUILD_BUG_ON(FAN_CREATE != FS_CREATE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 674) BUILD_BUG_ON(FAN_DELETE != FS_DELETE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 675) BUILD_BUG_ON(FAN_DELETE_SELF != FS_DELETE_SELF);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 676) BUILD_BUG_ON(FAN_MOVE_SELF != FS_MOVE_SELF);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 677) BUILD_BUG_ON(FAN_EVENT_ON_CHILD != FS_EVENT_ON_CHILD);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 678) BUILD_BUG_ON(FAN_Q_OVERFLOW != FS_Q_OVERFLOW);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 679) BUILD_BUG_ON(FAN_OPEN_PERM != FS_OPEN_PERM);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 680) BUILD_BUG_ON(FAN_ACCESS_PERM != FS_ACCESS_PERM);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 681) BUILD_BUG_ON(FAN_ONDIR != FS_ISDIR);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 682) BUILD_BUG_ON(FAN_OPEN_EXEC != FS_OPEN_EXEC);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 683) BUILD_BUG_ON(FAN_OPEN_EXEC_PERM != FS_OPEN_EXEC_PERM);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 684)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 685) BUILD_BUG_ON(HWEIGHT32(ALL_FANOTIFY_EVENT_BITS) != 19);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 686)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 687) mask = fanotify_group_event_mask(group, iter_info, mask, data,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 688) data_type, dir);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 689) if (!mask)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 690) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 691)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 692) pr_debug("%s: group=%p mask=%x\n", __func__, group, mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 693)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 694) if (fanotify_is_perm_event(mask)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 695) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 696) * fsnotify_prepare_user_wait() fails if we race with mark
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 697) * deletion. Just let the operation pass in that case.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 698) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 699) if (!fsnotify_prepare_user_wait(iter_info))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 700) return 0;
^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) if (FAN_GROUP_FLAG(group, FANOTIFY_FID_BITS)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 704) fsid = fanotify_get_fsid(iter_info);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 705) /* Racing with mark destruction or creation? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 706) if (!fsid.val[0] && !fsid.val[1])
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 707) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 708) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 709)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 710) event = fanotify_alloc_event(group, mask, data, data_type, dir,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 711) file_name, &fsid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 712) ret = -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 713) if (unlikely(!event)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 714) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 715) * We don't queue overflow events for permission events as
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 716) * there the access is denied and so no event is in fact lost.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 717) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 718) if (!fanotify_is_perm_event(mask))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 719) fsnotify_queue_overflow(group);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 720) goto finish;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 721) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 722)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 723) fsn_event = &event->fse;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 724) ret = fsnotify_add_event(group, fsn_event, fanotify_merge);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 725) if (ret) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 726) /* Permission events shouldn't be merged */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 727) BUG_ON(ret == 1 && mask & FANOTIFY_PERM_EVENTS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 728) /* Our event wasn't used in the end. Free it. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 729) fsnotify_destroy_event(group, fsn_event);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 730)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 731) ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 732) } else if (fanotify_is_perm_event(mask)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 733) ret = fanotify_get_response(group, FANOTIFY_PERM(event),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 734) iter_info);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 735) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 736) finish:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 737) if (fanotify_is_perm_event(mask))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 738) fsnotify_finish_user_wait(iter_info);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 739)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 740) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 741) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 742)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 743) static void fanotify_free_group_priv(struct fsnotify_group *group)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 744) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 745) struct user_struct *user;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 746)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 747) user = group->fanotify_data.user;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 748) atomic_dec(&user->fanotify_listeners);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 749) free_uid(user);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 750) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 751)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 752) static void fanotify_free_path_event(struct fanotify_event *event)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 753) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 754) path_put(fanotify_event_path(event));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 755) kmem_cache_free(fanotify_path_event_cachep, FANOTIFY_PE(event));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 756) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 757)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 758) static void fanotify_free_perm_event(struct fanotify_event *event)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 759) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 760) path_put(fanotify_event_path(event));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 761) kmem_cache_free(fanotify_perm_event_cachep, FANOTIFY_PERM(event));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 762) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 763)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 764) static void fanotify_free_fid_event(struct fanotify_event *event)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 765) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 766) struct fanotify_fid_event *ffe = FANOTIFY_FE(event);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 767)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 768) if (fanotify_fh_has_ext_buf(&ffe->object_fh))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 769) kfree(fanotify_fh_ext_buf(&ffe->object_fh));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 770) kmem_cache_free(fanotify_fid_event_cachep, ffe);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 771) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 772)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 773) static void fanotify_free_name_event(struct fanotify_event *event)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 774) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 775) kfree(FANOTIFY_NE(event));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 776) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 777)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 778) static void fanotify_free_event(struct fsnotify_event *fsn_event)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 779) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 780) struct fanotify_event *event;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 781)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 782) event = FANOTIFY_E(fsn_event);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 783) put_pid(event->pid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 784) switch (event->type) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 785) case FANOTIFY_EVENT_TYPE_PATH:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 786) fanotify_free_path_event(event);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 787) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 788) case FANOTIFY_EVENT_TYPE_PATH_PERM:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 789) fanotify_free_perm_event(event);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 790) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 791) case FANOTIFY_EVENT_TYPE_FID:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 792) fanotify_free_fid_event(event);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 793) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 794) case FANOTIFY_EVENT_TYPE_FID_NAME:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 795) fanotify_free_name_event(event);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 796) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 797) case FANOTIFY_EVENT_TYPE_OVERFLOW:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 798) kfree(event);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 799) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 800) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 801) WARN_ON_ONCE(1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 802) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 803) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 804)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 805) static void fanotify_free_mark(struct fsnotify_mark *fsn_mark)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 806) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 807) kmem_cache_free(fanotify_mark_cache, fsn_mark);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 808) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 809)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 810) const struct fsnotify_ops fanotify_fsnotify_ops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 811) .handle_event = fanotify_handle_event,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 812) .free_group_priv = fanotify_free_group_priv,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 813) .free_event = fanotify_free_event,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 814) .free_mark = fanotify_free_mark,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 815) };
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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