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authorEric Dumazet <edumazet@google.com>2015-08-13 15:44:51 -0700
committerDavid S. Miller <davem@davemloft.net>2015-08-13 22:46:22 -0700
commit83fccfc3940c4a2db90fd7e7079f5b465cd8c6af (patch)
tree054fec600d1a1b77d1ea73289423dd07db1b18a3 /net
parent2a4eebf0c485d8e90bdd2e33e75c4b3b1e1673ac (diff)
downloadlinux-83fccfc3940c4a2db90fd7e7079f5b465cd8c6af.tar.bz2
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')
-rw-r--r--net/ipv4/inet_connection_sock.c2
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;
}