Patch "sock: reset sk_err when the error queue is empty" has been added to the 4.11-stable tree

Patch "sock: reset sk_err when the error queue is empty" has been added to the 4.11-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    sock: reset sk_err when the error queue is empty

to the 4.11-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:
     sock-reset-sk_err-when-the-error-queue-is-empty.patch
and it can be found in the queue-4.11 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Thu Jun  8 08:58:08 CEST 2017
From: Soheil Hassas Yeganeh <soheil@google.com>
Date: Fri, 2 Jun 2017 12:38:22 -0400
Subject: sock: reset sk_err when the error queue is empty

From: Soheil Hassas Yeganeh <soheil@google.com>


[ Upstream commit 38b257938ac6655d0d6333743303231b9c465ec1 ]

Prior to f5f99309fa74 (sock: do not set sk_err in
sock_dequeue_err_skb), sk_err was reset to the error of
the skb on the head of the error queue.

Applications, most notably ping, are relying on this
behavior to reset sk_err for ICMP packets.

Set sk_err to the ICMP error when there is an ICMP packet
at the head of the error queue.

Fixes: f5f99309fa74 (sock: do not set sk_err in sock_dequeue_err_skb)
Reported-by: Cyril Hrubis <chrubis@suse.cz>
Tested-by: Cyril Hrubis <chrubis@suse.cz>
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/core/skbuff.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -3755,8 +3755,11 @@ struct sk_buff *sock_dequeue_err_skb(str
 
 	spin_lock_irqsave(&q->lock, flags);
 	skb = __skb_dequeue(q);
-	if (skb && (skb_next = skb_peek(q)))
+	if (skb && (skb_next = skb_peek(q))) {
 		icmp_next = is_icmp_err_skb(skb_next);
+		if (icmp_next)
+			sk->sk_err = SKB_EXT_ERR(skb_next)->ee.ee_origin;
+	}
 	spin_unlock_irqrestore(&q->lock, flags);
 
 	if (is_icmp_err_skb(skb) && !icmp_next)


Patches currently in stable-queue which might be from soheil@google.com are

queue-4.11/sock-reset-sk_err-when-the-error-queue-is-empty.patch
queue-4.11/tcp-disallow-cwnd-undo-when-switching-congestion-control.patch