From: Tetsuo Handa penguin-kernel@i-love.sakura.ne.jp
[ Upstream commit 0934ad42bb2c5df90a1b9de690f93de735b622fe ]
syzbot is reporting UAF at cipso_v4_doi_search() [1], for smk_cipso_doi() is calling kfree() without removing from the cipso_v4_doi_list list after netlbl_cfg_cipsov4_map_add() returned an error. We need to use netlbl_cfg_cipsov4_del() in order to remove from the list and wait for RCU grace period before kfree().
Link: https://syzkaller.appspot.com/bug?extid=93dba5b91f0fed312cbd [1] Reported-by: syzbot syzbot+93dba5b91f0fed312cbd@syzkaller.appspotmail.com Signed-off-by: Tetsuo Handa penguin-kernel@I-love.SAKURA.ne.jp Fixes: 6c2e8ac0953fccdd ("netlabel: Update kernel configuration API") Signed-off-by: Casey Schaufler casey@schaufler-ca.com Signed-off-by: Sasha Levin sashal@kernel.org --- security/smack/smackfs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c index 9fdf404a318f9..a9c516362170a 100644 --- a/security/smack/smackfs.c +++ b/security/smack/smackfs.c @@ -740,7 +740,7 @@ static void smk_cipso_doi(void) if (rc != 0) { printk(KERN_WARNING "%s:%d map add rc = %d\n", __func__, __LINE__, rc); - kfree(doip); + netlbl_cfg_cipsov4_del(doip->doi, &nai); return; } }