diff options
| author | Eric Dumazet <edumazet@google.com> | 2015-08-13 15:44:51 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-10-22 14:43:24 -0700 |
| commit | d3a1196bfc462943694623412d8e03aaf172bdc1 (patch) | |
| tree | a737edd76bf1ee1a78ff440b6620017680235f5e | |
| parent | a58897f9e663bb9b64b703f7dd451c7089cb28bb (diff) | |
inet: fix potential deadlock in reqsk_queue_unlink()
commit 83fccfc3940c4a2db90fd7e7079f5b465cd8c6af upstream.
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>
Cc: Holger Hoffstätte <holger.hoffstaette@googlemail.com>
Cc: Andre Tomt <andre@tomt.net>
Cc: Chris Caputo <ccaputo@alt.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -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; } |