]> git.ipfire.org Git - people/arne_f/kernel.git/commitdiff
Bluetooth: Avoid use of session socket after the session gets freed
authorVignesh Raman <Vignesh_Raman@mentor.com>
Tue, 22 Jul 2014 13:54:25 +0000 (19:24 +0530)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 17 Sep 2014 16:19:23 +0000 (09:19 -0700)
commit 32333edb82fb2009980eefc5518100068147ab82 upstream.

The commits 08c30aca9e698faddebd34f81e1196295f9dc063 "Bluetooth: Remove
RFCOMM session refcnt" and 8ff52f7d04d9cc31f1e81dcf9a2ba6335ed34905
"Bluetooth: Return RFCOMM session ptrs to avoid freed session"
allow rfcomm_recv_ua and rfcomm_session_close to delete the session
(and free the corresponding socket) and propagate NULL session pointer
to the upper callers.

Additional fix is required to terminate the loop in rfcomm_process_rx
function to avoid use of freed 'sk' memory.

The issue is only reproducible with kernel option CONFIG_PAGE_POISONING
enabled making freed memory being changed and filled up with fixed char
value used to unmask use-after-free issues.

Signed-off-by: Vignesh Raman <Vignesh_Raman@mentor.com>
Signed-off-by: Vitaly Kuzmichev <Vitaly_Kuzmichev@mentor.com>
Acked-by: Dean Jenkins <Dean_Jenkins@mentor.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net/bluetooth/rfcomm/core.c

index facd8a79c0383eb8898fca8dc905c87ed623202a..b0886511102417de84b15149848e07cf4ee5e746 100644 (file)
@@ -1859,10 +1859,13 @@ static struct rfcomm_session *rfcomm_process_rx(struct rfcomm_session *s)
        /* Get data directly from socket receive queue without copying it. */
        while ((skb = skb_dequeue(&sk->sk_receive_queue))) {
                skb_orphan(skb);
-               if (!skb_linearize(skb))
+               if (!skb_linearize(skb)) {
                        s = rfcomm_recv_frame(s, skb);
-               else
+                       if (!s)
+                               break;
+               } else {
                        kfree_skb(skb);
+               }
        }
 
        if (s && (sk->sk_state == BT_CLOSED))