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>
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 4667d4d..f2913ae 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -2992,7 +2992,11 @@
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);
}
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index b9d0d40..acdc9be 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -634,7 +634,9 @@
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);
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 87be586..3048f90 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -466,9 +466,11 @@
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: