recovery: Allow exec_type on dirs, read for /dev
When applying a file based OTA, the recovery scripts sometimes
transiently label a directory as an exec_type. This occurs on
hammerhead when the OTA generation scripts generate lines of the
form:
set_metadata_recursive("/system/vendor/bin", "uid", 0, "gid", 2000, "dmode", 0755, "fmode", 0755, "capabilities", 0x0, "selabel", "u:object_r:vss_exec:s0");
set_metadata("/system/vendor/bin", "uid", 0, "gid", 2000, "mode", 0755, "capabilities", 0x0, "selabel", "u:object_r:system_file:s0");
which has the effect of transiently labeling the /system/vendor/bin
directory as vss_exec.
Allow this behavior for now, even though it's obviously a bug.
Also, allow recovery to read through the /dev directory.
Addresses the following denials:
avc: denied { read } for pid=143 comm="recovery" name="/" dev="tmpfs" ino=8252 scontext=u:r:recovery:s0 tcontext=u:object_r:device:s0 tclass=dir
avc: denied { open } for pid=143 comm="recovery" name="/" dev="tmpfs" ino=8252 scontext=u:r:recovery:s0 tcontext=u:object_r:device:s0 tclass=dir
avc: denied { relabelto } for pid=142 comm="update_binary" name="bin" dev="mmcblk0p25" ino=1438 scontext=u:r:recovery:s0 tcontext=u:object_r:vss_exec:s0 tclass=dir
avc: denied { getattr } for pid=142 comm="update_binary" path="/system/vendor/bin" dev="mmcblk0p25" ino=1438 scontext=u:r:recovery:s0 tcontext=u:object_r:vss_exec:s0 tclass=dir
avc: denied { setattr } for pid=142 comm="update_binary" name="bin" dev="mmcblk0p25" ino=1438 scontext=u:r:recovery:s0 tcontext=u:object_r:vss_exec:s0 tclass=dir
avc: denied { relabelfrom } for pid=142 comm="update_binary" name="bin" dev="mmcblk0p25" ino=1438 scontext=u:r:recovery:s0 tcontext=u:object_r:vss_exec:s0 tclass=dir
Bug: 15575013
Change-Id: I743bea356382d3c23c136465dc5b434878370127
diff --git a/recovery.te b/recovery.te
index 5958761..df1e60d 100644
--- a/recovery.te
+++ b/recovery.te
@@ -25,11 +25,22 @@
allow recovery system_file:{ file lnk_file } { create_file_perms relabelfrom relabelto };
allow recovery system_file:dir { create_dir_perms relabelfrom relabelto };
+ # 0eb17d944704b3eb140bb9dded299d3be3aed77e in build/ added SELinux
+ # support to OTAs. However, that code has a bug. When an update occurs,
+ # some directories are inappropriately labeled as exec_type. This is
+ # only transient, and subsequent steps in the OTA script correct this
+ # mistake.
+ # Allow this behavior for now until we can fix the underlying bug.
+ # b/15575013
+ allow recovery exec_type:dir { create_dir_perms relabelfrom relabelto };
+ auditallow recovery exec_type:dir { create_dir_perms relabelfrom relabelto };
+
# Write to /proc/sys/vm/drop_caches
# TODO: create more specific label?
allow recovery proc:file w_file_perms;
# Required to e.g. wipe userdata/cache.
+ allow recovery device:dir r_dir_perms;
allow recovery block_device:dir r_dir_perms;
allow recovery dev_type:blk_file rw_file_perms;