android_kernel_sony_msm8994.../security
Al Viro e3fea3f70f selinux: fix selinux_inode_setxattr oops
OK, what we have so far is e.g.
	setxattr(path, name, whatever, 0, XATTR_REPLACE)
with name being good enough to get through xattr_permission().
Then we reach security_inode_setxattr() with the desired value and size.
Aha.  name should begin with "security.selinux", or we won't get that
far in selinux_inode_setxattr().  Suppose we got there and have enough
permissions to relabel that sucker.  We call security_context_to_sid()
with value == NULL, size == 0.  OK, we want ss_initialized to be non-zero.
I.e. after everything had been set up and running.  No problem...

We do 1-byte kmalloc(), zero-length memcpy() (which doesn't oops, even
thought the source is NULL) and put a NUL there.  I.e. form an empty
string.  string_to_context_struct() is called and looks for the first
':' in there.  Not found, -EINVAL we get.  OK, security_context_to_sid_core()
has rc == -EINVAL, force == 0, so it silently returns -EINVAL.
All it takes now is not having CAP_MAC_ADMIN and we are fucked.

All right, it might be a different bug (modulo strange code quoted in the
report), but it's real.  Easily fixed, AFAICS:

Deal with size == 0, value == NULL case in selinux_inode_setxattr()

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Tested-by: Dave Jones <davej@redhat.com>
Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2012-07-30 15:36:50 +10:00
..
apparmor split ->file_mmap() into ->mmap_addr()/->mmap_file() 2012-05-31 13:11:54 -04:00
integrity ima: audit is compiled only when enabled 2012-07-05 16:43:59 -04:00
keys Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2012-07-23 18:49:06 -07:00
selinux selinux: fix selinux_inode_setxattr oops 2012-07-30 15:36:50 +10:00
smack smack: off by one error 2012-07-30 15:04:17 +10:00
tomoyo Merge branch 'master' of git://git.infradead.org/users/eparis/selinux into next 2012-05-22 11:21:06 +10:00
yama Yama: replace capable() with ns_capable() 2012-05-15 10:27:57 +10:00
capability.c split ->file_mmap() into ->mmap_addr()/->mmap_file() 2012-05-31 13:11:54 -04:00
commoncap.c split ->file_mmap() into ->mmap_addr()/->mmap_file() 2012-05-31 13:11:54 -04:00
device_cgroup.c cgroup: convert all non-memcg controllers to the new cftype interface 2012-04-01 12:09:55 -07:00
inode.c securityfs: fix object creation races 2012-01-10 10:20:35 -05:00
Kconfig KEYS: Move the key config into security/keys/Kconfig 2012-05-11 10:56:56 +01:00
lsm_audit.c LSM: BUILD_BUG_ON if the common_audit_data union ever grows 2012-04-09 12:23:03 -04:00
Makefile security: Yama LSM 2012-02-10 09:18:52 +11:00
min_addr.c mmap_min_addr check CAP_SYS_RAWIO only for write 2010-04-23 08:56:31 +10:00
security.c security: Fix nommu build. 2012-07-03 21:41:03 +10:00