Re: unable to handle paging request, arm, at aio/tcp code, only 3.6

[Eric Dumazet <eric.dumazet@gmail.com>]

From: Eric Dumazet <edumazet@google.com>

> Thanks for the report.
> 
> I believe this is a regression of commit
> 35ad9b9cf7d8a2e6259a0d24022e910adb6f3489
> (ipv6: Add helper inet6_csk_update_pmtu().)
> 
> I'll prepare a patch to fix this.

Please try the following fix.

Thanks !

[PATCH] ipv6: fix inet6_csk_update_pmtu() return value

In case of error, inet6_csk_update_pmtu() should consistently
return NULL.

Bug added in commit 35ad9b9cf7d8a 
(ipv6: Add helper inet6_csk_update_pmtu().)

Reported-by: Lluís Batlle i Rossell <viric@viric.name>
Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 net/ipv6/inet6_connection_sock.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/ipv6/inet6_connection_sock.c b/net/ipv6/inet6_connection_sock.c
index c4f9341..3064785 100644
--- a/net/ipv6/inet6_connection_sock.c
+++ b/net/ipv6/inet6_connection_sock.c
@@ -252,6 +252,7 @@ struct dst_entry *inet6_csk_update_pmtu(struct sock *sk, u32 mtu)
 		return NULL;
 	dst->ops->update_pmtu(dst, sk, NULL, mtu);
 
-	return inet6_csk_route_socket(sk, &fl6);
+	dst = inet6_csk_route_socket(sk, &fl6);
+	return IS_ERR(dst) ? NULL : dst;
 }
 EXPORT_SYMBOL_GPL(inet6_csk_update_pmtu);