net: fix sk_forward_alloc corruptions

As David found out, sock_queue_err_skb() should be called with socket
lock hold, or we risk sk_forward_alloc corruption, since we use non
atomic operations to update this field.

This patch adds bh_lock_sock()/bh_unlock_sock() pair to three spots.
(BH already disabled)

1) skb_tstamp_tx() 
2) Before calling ip_icmp_error(), in __udp4_lib_err() 
3) Before calling ipv6_icmp_error(), in __udp6_lib_err()

Reported-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2010-05-29 00:20:48 -07:00 committed by David S. Miller
parent 7dfde179c3
commit 2903037400
3 changed files with 10 additions and 2 deletions

View File

@ -2992,7 +2992,11 @@ void skb_tstamp_tx(struct sk_buff *orig_skb,
memset(serr, 0, sizeof(*serr));
serr->ee.ee_errno = ENOMSG;
serr->ee.ee_origin = SO_EE_ORIGIN_TIMESTAMPING;
bh_lock_sock(sk);
err = sock_queue_err_skb(sk, skb);
bh_unlock_sock(sk);
if (err)
kfree_skb(skb);
}

View File

@ -634,7 +634,9 @@ void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable)
if (!harderr || sk->sk_state != TCP_ESTABLISHED)
goto out;
} else {
bh_lock_sock(sk);
ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1));
bh_unlock_sock(sk);
}
sk->sk_err = err;
sk->sk_error_report(sk);

View File

@ -466,9 +466,11 @@ void __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
if (sk->sk_state != TCP_ESTABLISHED && !np->recverr)
goto out;
if (np->recverr)
if (np->recverr) {
bh_lock_sock(sk);
ipv6_icmp_error(sk, skb, err, uh->dest, ntohl(info), (u8 *)(uh+1));
bh_unlock_sock(sk);
}
sk->sk_err = err;
sk->sk_error_report(sk);
out: