The bug was introduced 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 <[email protected]> Signed-off-by: Nicolas Dichtel <[email protected]> --- 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 7dde039374e4..2cd69e3497ad 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; -- 1.8.4.1 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
