This is a note to let you know that I've just added the patch titled
netlink: fix races after skb queueing
to the 3.0-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
netlink-fix-races-after-skb-queueing.patch
and it can be found in the queue-3.0 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From e8a68ff4e1b4ca9d5ab08d010c2a740bcddc993c Mon Sep 17 00:00:00 2001
From: Eric Dumazet <[email protected]>
Date: Thu, 5 Apr 2012 22:17:46 +0000
Subject: netlink: fix races after skb queueing
From: Eric Dumazet <[email protected]>
[ Upstream commit 4a7e7c2ad540e54c75489a70137bf0ec15d3a127 ]
As soon as an skb is queued into socket receive_queue, another thread
can consume it, so we are not allowed to reference skb anymore, or risk
use after free.
Signed-off-by: Eric Dumazet <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
net/netlink/af_netlink.c | 24 +++++++++++++-----------
1 file changed, 13 insertions(+), 11 deletions(-)
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -830,12 +830,19 @@ int netlink_attachskb(struct sock *sk, s
return 0;
}
-int netlink_sendskb(struct sock *sk, struct sk_buff *skb)
+static int __netlink_sendskb(struct sock *sk, struct sk_buff *skb)
{
int len = skb->len;
skb_queue_tail(&sk->sk_receive_queue, skb);
sk->sk_data_ready(sk, len);
+ return len;
+}
+
+int netlink_sendskb(struct sock *sk, struct sk_buff *skb)
+{
+ int len = __netlink_sendskb(sk, skb);
+
sock_put(sk);
return len;
}
@@ -960,8 +967,7 @@ static inline int netlink_broadcast_deli
if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf &&
!test_bit(0, &nlk->state)) {
skb_set_owner_r(skb, sk);
- skb_queue_tail(&sk->sk_receive_queue, skb);
- sk->sk_data_ready(sk, skb->len);
+ __netlink_sendskb(sk, skb);
return atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf;
}
return -1;
@@ -1682,10 +1688,8 @@ static int netlink_dump(struct sock *sk)
if (sk_filter(sk, skb))
kfree_skb(skb);
- else {
- skb_queue_tail(&sk->sk_receive_queue, skb);
- sk->sk_data_ready(sk, skb->len);
- }
+ else
+ __netlink_sendskb(sk, skb);
return 0;
}
@@ -1697,10 +1701,8 @@ static int netlink_dump(struct sock *sk)
if (sk_filter(sk, skb))
kfree_skb(skb);
- else {
- skb_queue_tail(&sk->sk_receive_queue, skb);
- sk->sk_data_ready(sk, skb->len);
- }
+ else
+ __netlink_sendskb(sk, skb);
if (cb->done)
cb->done(cb);
Patches currently in stable-queue which might be from [email protected] are
queue-3.0/net-fix-a-race-in-sock_queue_err_skb.patch
queue-3.0/tcp-allow-splice-to-build-full-tso-packets.patch
queue-3.0/net-smsc911x-fix-skb-handling-in-receive-path.patch
queue-3.0/netlink-fix-races-after-skb-queueing.patch
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