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>
---
net/bluetooth/rfcomm/core.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/net/bluetooth/rfcomm/core.c b/net/bluetooth/rfcomm/core.c
index 754b6fe..881f7de 100644
--- a/net/bluetooth/rfcomm/core.c
+++ b/net/bluetooth/rfcomm/core.c
@@ -1909,10 +1909,13 @@ 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))
--
1.7.9.5
--
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