4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet <edumazet@xxxxxxxxxx> commit 43a6684519ab0a6c52024b5e25322476cabad893 upstream. We got a report of yet another bug in ping http://www.openwall.com/lists/oss-security/2017/03/24/6 ->disconnect() is not called with socket lock held. Fix this by acquiring ping rwlock earlier. Thanks to Daniel, Alexander and Andrey for letting us know this problem. Fixes: c319b4d76b9e ("net: ipv4: add IPPROTO_ICMP socket kind") Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx> Reported-by: Daniel Jiang <danieljiang0415@xxxxxxxxx> Reported-by: Solar Designer <solar@xxxxxxxxxxxx> Reported-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Cc: Ben Hutchings <ben.hutchings@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/ipv4/ping.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/net/ipv4/ping.c +++ b/net/ipv4/ping.c @@ -156,17 +156,18 @@ int ping_hash(struct sock *sk) void ping_unhash(struct sock *sk) { struct inet_sock *isk = inet_sk(sk); + pr_debug("ping_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num); + write_lock_bh(&ping_table.lock); 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; sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); - write_unlock_bh(&ping_table.lock); } + write_unlock_bh(&ping_table.lock); } EXPORT_SYMBOL_GPL(ping_unhash);