[PATCH 3.16 121/158] Bluetooth: Avoid use of session socket after the session gets freed

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



3.16-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Vignesh Raman <Vignesh_Raman@xxxxxxxxxx>

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@xxxxxxxxxx>
Signed-off-by: Vitaly Kuzmichev <Vitaly_Kuzmichev@xxxxxxxxxx>
Acked-by: Dean Jenkins <Dean_Jenkins@xxxxxxxxxx>
Signed-off-by: Marcel Holtmann <marcel@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 net/bluetooth/rfcomm/core.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

--- a/net/bluetooth/rfcomm/core.c
+++ b/net/bluetooth/rfcomm/core.c
@@ -1909,10 +1909,13 @@ static struct rfcomm_session *rfcomm_pro
 	/* 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))


--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]