linux/security/smack
Casey Schaufler 57e7ba04d4 lsm: fix smack_inode_removexattr and xattr_getsecurity memleak
security_inode_getsecurity() provides the text string value
of a security attribute. It does not provide a "secctx".
The code in xattr_getsecurity() that calls security_inode_getsecurity()
and then calls security_release_secctx() happened to work because
SElinux and Smack treat the attribute and the secctx the same way.
It fails for cap_inode_getsecurity(), because that module has no
secctx that ever needs releasing. It turns out that Smack is the
one that's doing things wrong by not allocating memory when instructed
to do so by the "alloc" parameter.

The fix is simple enough. Change the security_release_secctx() to
kfree() because it isn't a secctx being returned by
security_inode_getsecurity(). Change Smack to allocate the string when
told to do so.

Note: this also fixes memory leaks for LSMs which implement
inode_getsecurity but not release_secctx, such as capabilities.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reported-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: stable@vger.kernel.org
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-10-04 18:03:15 +11:00
..
Kconfig Smack: Signal delivery as an append operation 2016-09-08 13:22:56 -07:00
Makefile Smack: Repair netfilter dependency 2015-01-23 10:08:19 -08:00
smack.h Smack: Use cap_capable in privilege check 2017-06-01 09:27:21 -07:00
smack_access.c Smack: Use cap_capable in privilege check 2017-06-01 09:27:21 -07:00
smack_lsm.c lsm: fix smack_inode_removexattr and xattr_getsecurity memleak 2017-10-04 18:03:15 +11:00
smack_netfilter.c netfilter: nf_hook_ops structs can be const 2017-07-31 19:10:44 +02:00
smackfs.c fs: constify tree_descr arrays passed to simple_fill_super() 2017-04-26 23:54:06 -04:00