Re: [PATCH v2 net] net: sk_clone_lock() should only do get_net() if the parent is not a kernel socket

2015-07-30 Thread David Miller
From: Sowmini Varadhan 
Date: Thu, 30 Jul 2015 15:50:36 +0200

> 
> 
> The newsk returned by sk_clone_lock should hold a get_net()
> reference if, and only if, the parent is not a kernel socket
> (making this similar to sk_alloc()).
> 
> E.g,. for the SYN_RECV path, tcp_v4_syn_recv_sock->..inet_csk_clone_lock
> sets up the syn_recv newsk from sk_clone_lock. When the parent (listen)
> socket is a kernel socket (defined in sk_alloc() as having
> sk_net_refcnt == 0), then the newsk should also have a 0 sk_net_refcnt
> and should not hold a get_net() reference.
> 
> Fixes: 26abe14379f8 ("net: Modify sk_alloc to not reference count the
>   netns of kernel sockets.")
> Acked-by: Eric Dumazet 
> Cc: Eric W. Biederman 
> Signed-off-by: Sowmini Varadhan 
> ---
> v2: pulled patch #3 out of the RFC patch-set for RDS-TCP netns fixes; 
> Added Fixes, Acked-by, Cc fields based on mailing list feedback
> from Eric Dumazet.

Applied, thanks everyone.
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[PATCH v2 net] net: sk_clone_lock() should only do get_net() if the parent is not a kernel socket

2015-07-30 Thread Sowmini Varadhan


The newsk returned by sk_clone_lock should hold a get_net()
reference if, and only if, the parent is not a kernel socket
(making this similar to sk_alloc()).

E.g,. for the SYN_RECV path, tcp_v4_syn_recv_sock->..inet_csk_clone_lock
sets up the syn_recv newsk from sk_clone_lock. When the parent (listen)
socket is a kernel socket (defined in sk_alloc() as having
sk_net_refcnt == 0), then the newsk should also have a 0 sk_net_refcnt
and should not hold a get_net() reference.

Fixes: 26abe14379f8 ("net: Modify sk_alloc to not reference count the
  netns of kernel sockets.")
Acked-by: Eric Dumazet 
Cc: Eric W. Biederman 
Signed-off-by: Sowmini Varadhan 
---
v2: pulled patch #3 out of the RFC patch-set for RDS-TCP netns fixes; 
Added Fixes, Acked-by, Cc fields based on mailing list feedback
from Eric Dumazet.

 net/core/sock.c |3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/net/core/sock.c b/net/core/sock.c
index 08f16db..371d1b7 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1497,7 +1497,8 @@ struct sock *sk_clone_lock(const struct sock *sk, const 
gfp_t priority)
sock_copy(newsk, sk);
 
/* SANITY */
-   get_net(sock_net(newsk));
+   if (likely(newsk->sk_net_refcnt))
+   get_net(sock_net(newsk));
sk_node_init(&newsk->sk_node);
sock_lock_init(newsk);
bh_lock_sock(newsk);
-- 
1.7.1

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html