From: Eric Dumazet <[email protected]> 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 <[email protected]> Reported-by: Daniel Jiang <[email protected]> Reported-by: Solar Designer <[email protected]> Reported-by: Andrey Konovalov <[email protected]> Signed-off-by: David S. Miller <[email protected]> [wt: the function is ping_v4_unhash() in 3.10] Signed-off-by: Willy Tarreau <[email protected]> --- net/ipv4/ping.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c index 431d597..0b778d7 100644 --- a/net/ipv4/ping.c +++ b/net/ipv4/ping.c @@ -135,17 +135,18 @@ static void ping_v4_hash(struct sock *sk) static void ping_v4_unhash(struct sock *sk) { struct inet_sock *isk = inet_sk(sk); + pr_debug("ping_v4_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); } static struct sock *ping_v4_lookup(struct net *net, __be32 saddr, __be32 daddr, -- 2.8.0.rc2.1.gbe9624a
