[PATCH] tcp: tcp_make_synack() should use sock_wmalloc

[PATCH] tcp: tcp_make_synack() should use sock_wmalloc

[Phil Oester]

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In commit 90ba9b19 (tcp: tcp_make_synack() can use alloc_skb()), Eric changed
the call to sock_wmalloc in tcp_make_synack to alloc_skb.  In doing so,
the netfilter owner match lost its ability to block the SYNACK packet on
outbound listening sockets.  Revert the change, restoring the owner match
functionality.

This closes netfilter bugzilla #847.

Signed-off-by: Phil Oester <kernel@linuxace.com>


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diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 92fde8d..362c5f7 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -2670,7 +2670,7 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,
 	int tcp_header_size;
 	int mss;
 
-	skb = alloc_skb(MAX_TCP_HEADER + 15, sk_gfp_atomic(sk, GFP_ATOMIC));
+	skb = sock_wmalloc(sk, MAX_TCP_HEADER + 15, 1, GFP_ATOMIC);
 	if (unlikely(!skb)) {
 		dst_release(dst);
 		return NULL;

Re: [PATCH] tcp: tcp_make_synack() should use sock_wmalloc

[David Miller]

From: Phil Oester <kernel@linuxace.com>
Date: Tue, 27 Aug 2013 16:41:40 -0700

> In commit 90ba9b19 (tcp: tcp_make_synack() can use alloc_skb()), Eric changed
> the call to sock_wmalloc in tcp_make_synack to alloc_skb.  In doing so,
> the netfilter owner match lost its ability to block the SYNACK packet on
> outbound listening sockets.  Revert the change, restoring the owner match
> functionality.
> 
> This closes netfilter bugzilla #847.
> 
> Signed-off-by: Phil Oester <kernel@linuxace.com>

Applied and queued up for -stable, thanks.

Eric, I guess if you really want to get rid of the wmem atomics you
can just attach the socket and make a special destructor.  Maybe it
is not even worth it at that point however.