Orange Pi5 kernel

^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/init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3) #include <linux/mm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4) #include <linux/security.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5) #include <linux/sysctl.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7) /* amount of vm to protect from userspace access by both DAC and the LSM*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8) unsigned long mmap_min_addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9) /* amount of vm to protect from userspace using CAP_SYS_RAWIO (DAC) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) unsigned long dac_mmap_min_addr = CONFIG_DEFAULT_MMAP_MIN_ADDR;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) /* amount of vm to protect from userspace using the LSM = CONFIG_LSM_MMAP_MIN_ADDR */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14)  * Update mmap_min_addr = max(dac_mmap_min_addr, CONFIG_LSM_MMAP_MIN_ADDR)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) static void update_mmap_min_addr(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #ifdef CONFIG_LSM_MMAP_MIN_ADDR
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) 	if (dac_mmap_min_addr > CONFIG_LSM_MMAP_MIN_ADDR)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) 		mmap_min_addr = dac_mmap_min_addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) 	else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) 		mmap_min_addr = CONFIG_LSM_MMAP_MIN_ADDR;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) #else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) 	mmap_min_addr = dac_mmap_min_addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) }
^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)  * sysctl handler which just sets dac_mmap_min_addr = the new value and then
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30)  * calls update_mmap_min_addr() so non MAP_FIXED hints get rounded properly
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) int mmap_min_addr_handler(struct ctl_table *table, int write,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) 			  void *buffer, size_t *lenp, loff_t *ppos)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) 	int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) 	if (write && !capable(CAP_SYS_RAWIO))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) 		return -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) 	ret = proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) 	update_mmap_min_addr();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) 	return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) static int __init init_mmap_min_addr(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) 	update_mmap_min_addr();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) pure_initcall(init_mmap_min_addr);