From: David S. Miller <davem@davemloft.net>
Date: Sat, 2 May 2015 02:02:47 +0000 (-0400)
Subject: ipv4: Missing sk_nulls_node_init() in ping_unhash().
X-Git-Tag: v4.1-rc2~6^2
X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=a134f083e79fb4c3d0a925691e732c56911b4326;p=linux.git

ipv4: Missing sk_nulls_node_init() in ping_unhash().

If we don't do that, then the poison value is left in the ->pprev
backlink.

This can cause crashes if we do a disconnect, followed by a connect().

Tested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reported-by: Wen Xu <hotdog3645@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c
index a93f260cf24c..05ff44b758df 100644
--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -158,6 +158,7 @@ void ping_unhash(struct sock *sk)
 	if (sk_hashed(sk)) {
 		write_lock_bh(&ping_table.lock);
 		hlist_nulls_del(&sk->sk_nulls_node);
+		sk_nulls_node_init(&sk->sk_nulls_node);
 		sock_put(sk);
 		isk->inet_num = 0;
 		isk->inet_sport = 0;