From 92b95364235b6441a36861ff0ca4541a13351d60 Mon Sep 17 00:00:00 2001 From: Paolo Abeni Date: Thu, 21 Feb 2019 17:44:00 +0100 Subject: udp: fix possible user after free in error handler Similar to the previous commit, this addresses the same issue for ipv4: use a single fetch operation and use the correct rcu annotation. Fixes: e7cc082455cb ("udp: Support for error handlers of tunnels with arbitrary destination port") Signed-off-by: Paolo Abeni Acked-by: Stefano Brivio Signed-off-by: David S. Miller --- net/ipv4/udp.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'net') diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 5c3cd5d84a6f..372fdc5381a9 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -562,10 +562,12 @@ static int __udp4_lib_err_encap_no_sk(struct sk_buff *skb, u32 info) for (i = 0; i < MAX_IPTUN_ENCAP_OPS; i++) { int (*handler)(struct sk_buff *skb, u32 info); + const struct ip_tunnel_encap_ops *encap; - if (!iptun_encaps[i]) + encap = rcu_dereference(iptun_encaps[i]); + if (!encap) continue; - handler = rcu_dereference(iptun_encaps[i]->err_handler); + handler = encap->err_handler; if (handler && !handler(skb, info)) return 0; } -- cgit v1.2.3-59-g8ed1b