| From: Eric Dumazet <edumazet@google.com> |
| Date: Fri, 24 Mar 2017 19:36:13 -0700 |
| Subject: ping: implement proper locking |
| |
| 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@google.com> |
| Reported-by: Daniel Jiang <danieljiang0415@gmail.com> |
| Reported-by: Solar Designer <solar@openwall.com> |
| Reported-by: Andrey Konovalov <andreyknvl@google.com> |
| Signed-off-by: David S. Miller <davem@davemloft.net> |
| Signed-off-by: Ben Hutchings <ben@decadent.org.uk> |
| --- |
| net/ipv4/ping.c | 5 +++-- |
| 1 file changed, 3 insertions(+), 2 deletions(-) |
| |
| --- a/net/ipv4/ping.c |
| +++ b/net/ipv4/ping.c |
| @@ -154,17 +154,18 @@ void 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); |
| |
