From: Eric Dumazet Date: Sat, 25 Mar 2017 02:36:13 +0000 (-0700) Subject: ping: implement proper locking X-Git-Tag: archive/raspbian/4.15.4-1+rpi1~1^2^2^2^2^2^2^2^2^2^2^2^2^2~37 X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=382705b02f89241b9d5f54988eb357f53734cf32;p=linux.git ping: implement proper locking 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 Reported-by: Daniel Jiang Reported-by: Solar Designer Reported-by: Andrey Konovalov Signed-off-by: David S. Miller Gbp-Pq: Topic bugfix/all Gbp-Pq: Name ping-implement-proper-locking.patch --- diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c index 105c0748c52..e612991c918 100644 --- 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);