Re: [PATCH net] sock: reset sk_err when the error queue is empty

[David Miller]

From: Soheil Hassas Yeganeh 
Date: Fri,  2 Jun 2017 12:38:22 -0400

> From: Soheil Hassas Yeganeh 
> 
> 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 
> Test-by: Cyril Hrubis 
> Signed-off-by: Soheil Hassas Yeganeh 
> Signed-off-by: Eric Dumazet 
> Signed-off-by: Willem de Bruijn 

Applied and queued up for -stable, thank you.

[PATCH net] sock: reset sk_err when the error queue is empty

[Soheil Hassas Yeganeh]

From: Soheil Hassas Yeganeh 

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 
Test-by: Cyril Hrubis 
Signed-off-by: Soheil Hassas Yeganeh 
Signed-off-by: Eric Dumazet 
Signed-off-by: Willem de Bruijn 
---
 net/core/skbuff.c | 5 -
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 346d3e85dfbc..b1be7c01efe2 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -3754,8 +3754,11 @@ struct sk_buff *sock_dequeue_err_skb(struct sock *sk)
 
spin_lock_irqsave(>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(>lock, flags);
 
if (is_icmp_err_skb(skb) && !icmp_next)
-- 
2.13.0.506.g27d5fe0cd-goog