BACKPORT: Smack: Fix possible NULL pointer dereference at smk_netlbl_mls()

netlbl_secattr_catmap_alloc(GFP_ATOMIC) can return NULL.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
(cherry-picked from upstream 8cd77a0bd4b4a7d02c2a6926a69585d8088ee721)

diff --git a/security/smack/smack_access.c b/security/smack/smack_access.c
index 53f2327a592f51422d88fcc0c459402c15e8c2b7..6a0377f38620acd318444a399c2fc4ef8227c3db 100644 (file)
--- a/security/smack/smack_access.c
+++ b/security/smack/smack_access.c
@@ -403,6 +403,8 @@ int smk_netlbl_mls(int level, char *catset, struct netlbl_lsm_secattr *sap,
        sap->flags |= NETLBL_SECATTR_MLS_CAT;
        sap->attr.mls.lvl = level;
        sap->attr.mls.cat = netlbl_secattr_catmap_alloc(GFP_ATOMIC);
+       if (!sap->attr.mls.cat)
+               return -ENOMEM;
        sap->attr.mls.cat->startbit = 0;
 
        for (cat = 1, cp = catset, byte = 0; byte < len; cp++, byte++)