From: Soheil Hassas Yeganeh <soheil@google.com>
Date: Fri, 2 Jun 2017 16:38:22 +0000 (-0400)
Subject: sock: reset sk_err when the error queue is empty
X-Git-Tag: v4.11.5~141
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=19456d4526558a83d7e7c0301b829ed998937bb0;p=thirdparty%2Fkernel%2Fstable.git

sock: reset sk_err when the error queue is empty


[ 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>
---

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index f1d04592ace02..ac5059aad3130 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -3755,8 +3755,11 @@ struct sk_buff *sock_dequeue_err_skb(struct sock *sk)
 
 	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)