linux/security
Stephen Smalley bb62683e68 selinux: fix inode security list corruption
commit 923190d32d upstream.

sb_finish_set_opts() can race with inode_free_security()
when initializing inode security structures for inodes
created prior to initial policy load or by the filesystem
during ->mount().   This appears to have always been
a possible race, but commit 3dc91d4 ("SELinux:  Fix possible
NULL pointer dereference in selinux_inode_permission()")
made it more evident by immediately reusing the unioned
list/rcu element  of the inode security structure for call_rcu()
upon an inode_free_security().  But the underlying issue
was already present before that commit as a possible use-after-free
of isec.

Shivnandan Kumar reported the list corruption and proposed
a patch to split the list and rcu elements out of the union
as separate fields of the inode_security_struct so that setting
the rcu element would not affect the list element.  However,
this would merely hide the issue and not truly fix the code.

This patch instead moves up the deletion of the list entry
prior to dropping the sbsec->isec_lock initially.  Then,
if the inode is dropped subsequently, there will be no further
references to the isec.

Reported-by: Shivnandan Kumar <shivnandan.k@samsung.com>
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <pmoore@redhat.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
History 2014-11-17 14:11:41 +00:00
..
apparmor nick kvfree() from apparmor 2014-05-06 14:02:53 -04:00
integrity evm: properly handle INTEGRITY_NOXATTRS EVM status 2014-11-14 15:20:09 +00:00
keys Merge branch 'serge-next-1' of git://git.kernel.org/pub/scm/linux/kernel/git/sergeh/linux-security 2014-06-10 10:05:36 -07:00
selinux selinux: fix inode security list corruption 2014-11-17 14:11:41 +00:00
smack Merge branch 'smack-for-3.16' of git://git.gitorious.org/smack-next/kernel into next 2014-05-20 14:50:09 +10:00
tomoyo get rid of pointless checks for NULL ->i_op 2014-04-01 23:19:16 -04:00
yama yama: Better permission check for ptraceme 2013-03-26 13:17:58 -07:00
capability.c Merge tag 'keys-20140314' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs into next 2014-04-14 11:42:49 +10:00
commoncap.c CAPABILITIES: remove undefined caps from all processes 2014-09-17 09:21:53 -07:00
device_cgroup.c device_cgroup: use css_has_online_children() instead of has_children() 2014-05-16 13:22:52 -04:00
inode.c securityfs: fix object creation races 2012-01-10 10:20:35 -05:00
Kconfig security: select correct default LSM_MMAP_MIN_ADDR on arm on arm64 2014-02-05 14:59:14 +00:00
lsm_audit.c audit: anchor all pid references in the initial pid namespace 2014-03-20 10:11:55 -04:00
Makefile security: cleanup Makefiles to use standard syntax for specifying sub-directories 2014-02-17 11:08:04 +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 Merge branch 'serge-next-1' of git://git.kernel.org/pub/scm/linux/kernel/git/sergeh/linux-security 2014-06-10 10:05:36 -07:00