585d9767c0
To determine if it is safe to run fsck on a filesystem, e2fsck
must first determine if the filesystem is mounted. To do that,
e2fsck scans through /proc/mounts and collects all the mounted
block devices. With that information, it runs stat() on each block
device, comparing the major and minor numbers to the filesystem
passed in on the command line. If there is a match, then the filesystem
is currently mounted and running fsck is dangerous.
Allow stat access to all block devices so that fsck can compare
major/minor values.
Addresses the following denials:
avc: denied { getattr } for comm="e2fsck" path="/dev/block/sde5"
dev="tmpfs" ino=15649 scontext=u:r:fsck:s0
tcontext=u:object_r:metadata_block_device:s0 tclass=blk_file
permissive=0
avc: denied { getattr } for comm="e2fsck" path="/dev/block/sda25"
dev="tmpfs" ino=15528 scontext=u:r:fsck:s0
tcontext=u:object_r:modem_block_device:s0 tclass=blk_file permissive=0
avc: denied { getattr } for comm="e2fsck" path="/dev/block/sda31"
dev="tmpfs" ino=15552 scontext=u:r:fsck:s0
tcontext=u:object_r:system_block_device:s0 tclass=blk_file permissive=0
avc: denied { getattr } for comm="e2fsck" path="/dev/block/sdd3"
dev="tmpfs" ino=15600 scontext=u:r:fsck:s0
tcontext=u:object_r:block_device:s0 tclass=blk_file permissive=0
Bug: 35324014
Bug: 33781554
Test: device boots and no SELinux denials.
Change-Id: I5af4a334ec41952887914eec4eee5c60cc441a66
56 lines
1.8 KiB
Plaintext
56 lines
1.8 KiB
Plaintext
# Any fsck program run by init
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type fsck, domain, domain_deprecated;
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type fsck_exec, exec_type, file_type;
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# /dev/__null__ created by init prior to policy load,
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# open fd inherited by fsck.
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allow fsck tmpfs:chr_file { read write ioctl };
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# Inherit and use pty created by android_fork_execvp_ext().
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allow fsck devpts:chr_file { read write ioctl getattr };
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# Allow stdin/out back to vold
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allow fsck vold:fd use;
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allow fsck vold:fifo_file { read write getattr };
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# Run fsck on certain block devices
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allow fsck block_device:dir search;
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allow fsck userdata_block_device:blk_file rw_file_perms;
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allow fsck cache_block_device:blk_file rw_file_perms;
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allow fsck dm_device:blk_file rw_file_perms;
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# To determine if it is safe to run fsck on a filesystem, e2fsck
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# must first determine if the filesystem is mounted. To do that,
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# e2fsck scans through /proc/mounts and collects all the mounted
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# block devices. With that information, it runs stat() on each block
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# device, comparing the major and minor numbers to the filesystem
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# passed in on the command line. If there is a match, then the filesystem
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# is currently mounted and running fsck is dangerous.
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# Allow stat access to all block devices so that fsck can compare
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# major/minor values.
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allow fsck dev_type:blk_file getattr;
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r_dir_file(fsck, proc)
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allow fsck rootfs:dir r_dir_perms;
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###
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### neverallow rules
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###
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# fsck should never be run on these block devices
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neverallow fsck {
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boot_block_device
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frp_block_device
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metadata_block_device
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recovery_block_device
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root_block_device
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swap_block_device
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system_block_device
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vold_device
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}:blk_file no_rw_file_perms;
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# Only allow entry from init or vold via fsck binaries
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neverallow { domain -init -vold } fsck:process transition;
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neverallow * fsck:process dyntransition;
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neverallow fsck { file_type fs_type -fsck_exec }:file entrypoint;
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