Commit 352651a0 authored by Eric Dumazet's avatar Eric Dumazet Committed by Ben Hutchings

ping: implement proper locking

commit 43a66845 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: c319b4d7 ("net: ipv4: add IPPROTO_ICMP socket kind")
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Reported-by: default avatarDaniel Jiang <danieljiang0415@gmail.com>
Reported-by: default avatarSolar Designer <solar@openwall.com>
Reported-by: default avatarAndrey Konovalov <andreyknvl@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
parent 7488aaea
...@@ -135,16 +135,17 @@ static void ping_v4_hash(struct sock *sk) ...@@ -135,16 +135,17 @@ static void ping_v4_hash(struct sock *sk)
static void ping_v4_unhash(struct sock *sk) static void ping_v4_unhash(struct sock *sk)
{ {
struct inet_sock *isk = inet_sk(sk); struct inet_sock *isk = inet_sk(sk);
pr_debug("ping_v4_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num); pr_debug("ping_v4_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num);
if (sk_hashed(sk)) {
write_lock_bh(&ping_table.lock); write_lock_bh(&ping_table.lock);
if (sk_hashed(sk)) {
hlist_nulls_del(&sk->sk_nulls_node); hlist_nulls_del(&sk->sk_nulls_node);
sk_nulls_node_init(&sk->sk_nulls_node); sk_nulls_node_init(&sk->sk_nulls_node);
sock_put(sk); sock_put(sk);
isk->inet_num = isk->inet_sport = 0; isk->inet_num = isk->inet_sport = 0;
sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); 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, u32 saddr, u32 daddr, static struct sock *ping_v4_lookup(struct net *net, u32 saddr, u32 daddr,
......
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