lkml.org 
[lkml]   [2012]   [Feb]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[20/21] net: fix sk_forward_alloc corruptions
2.6.32-longterm review patch.  If anyone has any objections, please let me know.

------------------
From: Eric Dumazet <eric.dumazet@gmail.com>

commit 2903037400a26e7c0cc93ab75a7d62abfacdf485 upstream.

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>
Cc: 单卫 <shanwei88@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
net/core/skbuff.c | 4 ++++
net/ipv4/udp.c | 2 ++
net/ipv6/udp.c | 6 ++++--
3 files changed, 10 insertions(+), 2 deletions(-)
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -3008,7 +3008,11 @@ void skb_tstamp_tx(struct sk_buff *orig_
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);
}
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -441,7 +441,9 @@ void __udp4_lib_err(struct sk_buff *skb,
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);
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -337,9 +337,11 @@ void __udp6_lib_err(struct sk_buff *skb,
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:



\
 
 \ /
  Last update: 2012-02-10 23:55    [from the cache]
©2003-2011 Jasper Spaans