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author | Eric Dumazet <eric.dumazet@gmail.com> | 2011-11-02 23:47:44 +0100 |
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committer | David S. Miller <davem@davemloft.net> | 2011-11-03 23:02:13 +0100 |
commit | e2e210c0238eb7073e07af503ae743fa53977120 (patch) | |
tree | a4940a436eb0292f09a9e9c09d7bfccfc5a0d76f /net | |
parent | net: fix typo in drivers/net/ethernet/xilinx/ll_temac_main.c (diff) | |
download | linux-e2e210c0238eb7073e07af503ae743fa53977120.tar.xz linux-e2e210c0238eb7073e07af503ae743fa53977120.zip |
l2tp: fix race in l2tp_recv_dequeue()
Misha Labjuk reported panics occurring in l2tp_recv_dequeue()
If we release reorder_q.lock, we must not keep a dangling pointer (tmp),
since another thread could manipulate reorder_q.
Instead we must restart the scan at beginning of list.
Reported-by: Misha Labjuk <spiked.yar@gmail.com>
Tested-by: Misha Labjuk <spiked.yar@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r-- | net/l2tp/l2tp_core.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c index 34b2ddeacb67..bf8d50c67931 100644 --- a/net/l2tp/l2tp_core.c +++ b/net/l2tp/l2tp_core.c @@ -397,6 +397,7 @@ static void l2tp_recv_dequeue(struct l2tp_session *session) * expect to send up next, dequeue it and any other * in-sequence packets behind it. */ +start: spin_lock_bh(&session->reorder_q.lock); skb_queue_walk_safe(&session->reorder_q, skb, tmp) { if (time_after(jiffies, L2TP_SKB_CB(skb)->expires)) { @@ -433,7 +434,7 @@ static void l2tp_recv_dequeue(struct l2tp_session *session) */ spin_unlock_bh(&session->reorder_q.lock); l2tp_recv_dequeue_skb(session, skb); - spin_lock_bh(&session->reorder_q.lock); + goto start; } out: |