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| author | Eric Dumazet <edumazet@google.com> | 2015-08-14 01:44:51 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-08-14 08:46:22 +0300 |
| commit | 83fccfc3940c4a2db90fd7e7079f5b465cd8c6af (patch) | |
| tree | 054fec600d1a1b77d1ea73289423dd07db1b18a3 /net/ipv4/inet_connection_sock.c | |
| parent | 2a4eebf0c485d8e90bdd2e33e75c4b3b1e1673ac (diff) | |
| download | linux-83fccfc3940c4a2db90fd7e7079f5b465cd8c6af.tar.xz | |
inet: fix potential deadlock in reqsk_queue_unlink()
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>
Diffstat (limited to 'net/ipv4/inet_connection_sock.c')
| -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 05e3145f7dc3..134957159c27 100644 --- a/net/ipv4/inet_connection_sock.c +++ b/net/ipv4/inet_connection_sock.c @@ -593,7 +593,7 @@ 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; } |