| Date | Mon, 12 May 2014 02:33:52 +0200 | From | Willy Tarreau <> | Subject | [ 112/143] sctp: unbalanced rcu lock in ip_queue_xmit() |
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2.6.32-longterm review patch. If anyone has any objections, please let me know.
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From: Nicolas Dichtel <nicolas.dichtel@6wind.com>
The bug was introduced in 2.6.32.61 by commit b8710128e201 ("inet: add RCU protection to inet->opt") (it's a backport of upstream commit f6d8bd051c39).
In SCTP case, packet is already routed, hence we jump to the label 'packet_routed', but without rcu_read_lock(). After this label, rcu_read_unlock() is called unconditionally.
Spotted-by: Guo Fengtian <fengtian.guo@6wind.com> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: Willy Tarreau <w@1wt.eu> --- net/ipv4/ip_output.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index 7dde039..2cd69e3 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -320,13 +320,13 @@ int ip_queue_xmit(struct sk_buff *skb, int ipfragok) /* Skip all of this if the packet is already routed, * f.e. by something like SCTP. */ + rcu_read_lock(); rt = skb_rtable(skb); if (rt != NULL) goto packet_routed; /* Make sure we can route this packet. */ rt = (struct rtable *)__sk_dst_check(sk, 0); - rcu_read_lock(); inet_opt = rcu_dereference(inet->inet_opt); if (rt == NULL) { __be32 daddr; -- 1.7.12.2.21.g234cd45.dirty
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