platform_system_sepolicy/public/lmkd.te
Benjamin Gordon 342362ae3e sepolicy: grant dac_read_search to domains with dac_override
kernel commit 2a4c22426955d4fc04069811997b7390c0fb858e (fs: switch order
of CAP_DAC_OVERRIDE and CAP_DAC_READ_SEARCH checks) swapped the order of
dac_override and dac_read_search checks.  Domains that have dac_override
will now generate spurious denials for dac_read_search unless they also
have that permission.  Since dac_override is a strict superset of
dac_read_search, grant dac_read_search to all domains that already have
dac_override to get rid of the denials.

Bug: 114280985
Bug: crbug.com/877588
Test: Booted on a device running 4.14.
Change-Id: I5c1c136b775cceeb7f170e139e8d4279e73267a4
2018-09-19 15:54:37 -06:00

55 lines
1.6 KiB
Text

# lmkd low memory killer daemon
type lmkd, domain, mlstrustedsubject;
type lmkd_exec, exec_type, file_type;
allow lmkd self:global_capability_class_set { dac_override dac_read_search sys_resource kill };
# lmkd locks itself in memory, to prevent it from being
# swapped out and unable to kill other memory hogs.
# system/core commit b28ff9131363f7b4a698990da5748b2a88c3ed35
# b/16236289
allow lmkd self:global_capability_class_set ipc_lock;
## Open and write to /proc/PID/oom_score_adj
## TODO: maybe scope this down?
r_dir_file(lmkd, appdomain)
allow lmkd appdomain:file write;
r_dir_file(lmkd, system_server)
allow lmkd system_server:file write;
## Writes to /sys/module/lowmemorykiller/parameters/minfree
r_dir_file(lmkd, sysfs_lowmemorykiller)
allow lmkd sysfs_lowmemorykiller:file w_file_perms;
# Send kill signals
allow lmkd appdomain:process sigkill;
# Clean up old cgroups
allow lmkd cgroup:dir { remove_name rmdir };
# Allow to read memcg stats
allow lmkd cgroup:file r_file_perms;
# Set self to SCHED_FIFO
allow lmkd self:global_capability_class_set sys_nice;
allow lmkd proc_zoneinfo:file r_file_perms;
# Set sys.lmk.* properties.
set_prop(lmkd, system_lmk_prop)
# live lock watchdog process allowed to look through /proc/
allow lmkd domain:dir { search open read };
allow lmkd domain:file { open read };
# live lock watchdog process allowed to dump process trace and
# reboot because orderly shutdown may not be possible.
allow lmkd proc_sysrq:file rw_file_perms;
# Read /proc/meminfo
allow lmkd proc_meminfo:file r_file_perms;
### neverallow rules
# never honor LD_PRELOAD
neverallow * lmkd:process noatsecure;