| Inseob Kim | ff43be2 | 2021-06-07 16:56:56 +0900 | [diff] [blame] | 1 | # Any fsck program run by init |
| 2 | type fsck, domain; |
| 3 | type fsck_exec, system_file_type, exec_type, file_type; |
| 4 | |
| 5 | # /dev/__null__ created by init prior to policy load, |
| 6 | # open fd inherited by fsck. |
| 7 | allow fsck tmpfs:chr_file { read write ioctl }; |
| 8 | |
| 9 | # Inherit and use pty created by android_fork_execvp_ext(). |
| 10 | allow fsck devpts:chr_file { read write ioctl getattr }; |
| 11 | |
| 12 | # Allow stdin/out back to vold |
| 13 | allow fsck vold:fd use; |
| 14 | allow fsck vold:fifo_file { read write getattr }; |
| 15 | |
| 16 | # Run fsck on certain block devices |
| 17 | allow fsck block_device:dir search; |
| 18 | allow fsck userdata_block_device:blk_file rw_file_perms; |
| 19 | allow fsck cache_block_device:blk_file rw_file_perms; |
| 20 | allow fsck dm_device:blk_file rw_file_perms; |
| 21 | userdebug_or_eng(` |
| 22 | allow fsck system_block_device:blk_file rw_file_perms; |
| 23 | ') |
| 24 | |
| 25 | # For the block devices where we have ioctl access, |
| 26 | # allow at a minimum the following common fsck ioctls. |
| 27 | allowxperm fsck dev_type:blk_file ioctl { |
| 28 | BLKDISCARDZEROES |
| 29 | BLKROGET |
| 30 | }; |
| 31 | |
| 32 | # To determine if it is safe to run fsck on a filesystem, e2fsck |
| 33 | # must first determine if the filesystem is mounted. To do that, |
| 34 | # e2fsck scans through /proc/mounts and collects all the mounted |
| 35 | # block devices. With that information, it runs stat() on each block |
| 36 | # device, comparing the major and minor numbers to the filesystem |
| 37 | # passed in on the command line. If there is a match, then the filesystem |
| 38 | # is currently mounted and running fsck is dangerous. |
| 39 | # Allow stat access to all block devices so that fsck can compare |
| 40 | # major/minor values. |
| 41 | allow fsck dev_type:blk_file getattr; |
| 42 | |
| 43 | allow fsck { |
| 44 | proc_mounts |
| 45 | proc_swaps |
| 46 | }:file r_file_perms; |
| 47 | allow fsck rootfs:dir r_dir_perms; |
| 48 | |
| 49 | ### |
| 50 | ### neverallow rules |
| 51 | ### |
| 52 | |
| 53 | # fsck should never be run on these block devices |
| 54 | neverallow fsck { |
| 55 | boot_block_device |
| 56 | frp_block_device |
| 57 | recovery_block_device |
| 58 | root_block_device |
| 59 | swap_block_device |
| 60 | system_block_device |
| 61 | userdebug_or_eng(`-system_block_device') |
| 62 | vold_device |
| 63 | }:blk_file no_rw_file_perms; |
| 64 | |
| 65 | # Only allow entry from init or vold via fsck binaries |
| 66 | neverallow { domain -init -vold } fsck:process transition; |
| 67 | neverallow * fsck:process dyntransition; |
| 68 | neverallow fsck { file_type fs_type -fsck_exec }:file entrypoint; |