From c9f2c1ae123a751d4e4f949144500219354d5ee1 Mon Sep 17 00:00:00 2001 From: Paolo Abeni Date: Thu, 27 Jul 2017 14:45:09 +0200 Subject: udp6: fix socket leak on early demux When an early demuxed packet reaches __udp6_lib_lookup_skb(), the sk reference is retrieved and used, but the relevant reference count is leaked and the socket destructor is never called. Beyond leaking the sk memory, if there are pending UDP packets in the receive queue, even the related accounted memory is leaked. In the long run, this will cause persistent forward allocation errors and no UDP skbs (both ipv4 and ipv6) will be able to reach the user-space. Fix this by explicitly accessing the early demux reference before the lookup, and properly decreasing the socket reference count after usage. Also drop the skb_steal_sock() in __udp6_lib_lookup_skb(), and the now obsoleted comment about "socket cache". The newly added code is derived from the current ipv4 code for the similar path. v1 -> v2: fixed the __udp6_lib_rcv() return code for resubmission, as suggested by Eric Reported-by: Sam Edwards Reported-by: Marc Haber Fixes: 5425077d73e0 ("net: ipv6: Add early demux handler for UDP unicast") Signed-off-by: Paolo Abeni Acked-by: Eric Dumazet Signed-off-by: David S. Miller --- include/net/udp.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/net') diff --git a/include/net/udp.h b/include/net/udp.h index 56ce2d2a612d..cc8036987dcb 100644 --- a/include/net/udp.h +++ b/include/net/udp.h @@ -260,6 +260,7 @@ static inline struct sk_buff *skb_recv_udp(struct sock *sk, unsigned int flags, } void udp_v4_early_demux(struct sk_buff *skb); +void udp_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst); int udp_get_port(struct sock *sk, unsigned short snum, int (*saddr_cmp)(const struct sock *, const struct sock *)); -- cgit v1.2.3