diff options
| author | Eric Dumazet <edumazet@google.com> | 2015-08-13 15:44:51 -0700 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2015-10-31 13:46:51 +0100 |
| commit | 79dcec543cb3b79fb6b3921d8f836272871dfd36 (patch) | |
| tree | 9b8805d38ca4868d2ccd841e7417e404f3a0c471 | |
| parent | 16dbe9c0de159a3c2803ed7aac4892ddc5ba0b6b (diff) | |
inet: fix potential deadlock in reqsk_queue_unlink()
Upstream commit: 83fccfc3940c
When replacing del_timer() with del_timer_sync(), I introduced
a deadlock condition :
reqsk_queue_unlink() is called from inet_csk_reqsk_queue_drop()
inet_csk_reqsk_queue_drop() can be called from many contexts,
one being the timer handler itself (reqsk_timer_handler()).
In this case, del_timer_sync() loops forever.
Simple fix is to test if timer is pending.
Fixes: 2235f2ac75fd ("inet: fix races with reqsk timers")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/ipv4/inet_connection_sock.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c index b27fc401c6a9..e664706b350c 100644 --- a/net/ipv4/inet_connection_sock.c +++ b/net/ipv4/inet_connection_sock.c @@ -584,7 +584,7 @@ static bool reqsk_queue_unlink(struct request_sock_queue *queue, } spin_unlock(&queue->syn_wait_lock); - if (del_timer_sync(&req->rsk_timer)) + if (timer_pending(&req->rsk_timer) && del_timer_sync(&req->rsk_timer)) reqsk_put(req); return found; } |