[3.13.y.z extended stable] Patch "tipc: clear 'next'-pointer of message fragments before reassembly" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    tipc: clear 'next'-pointer of message fragments before reassembly

to the linux-3.13.y-queue branch of the 3.13.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11.6.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 775e2b350bdfff30e74bf0fda4b0dd1a7afab695 Mon Sep 17 00:00:00 2001
From: Jon Paul Maloy <jon.maloy at ericsson.com>
Date: Fri, 11 Jul 2014 08:45:27 -0400
Subject: tipc: clear 'next'-pointer of message fragments before reassembly

[ Upstream commit 999417549c16dd0e3a382aa9f6ae61688db03181 ]

If the 'next' pointer of the last fragment buffer in a message is not
zeroed before reassembly, we risk ending up with a corrupt message,
since the reassembly function itself isn't doing this.

Currently, when a buffer is retrieved from the deferred queue of the
broadcast link, the next pointer is not cleared, with the result as
described above.

This commit corrects this, and thereby fixes a bug that may occur when
long broadcast messages are transmitted across dual interfaces. The bug
has been present since 40ba3cdf542a469aaa9083fa041656e59b109b90 ("tipc:
message reassembly using fragment chain")

This commit should be applied to both net and net-next.

Signed-off-by: Jon Maloy <jon.maloy at ericsson.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 net/tipc/bcast.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/tipc/bcast.c b/net/tipc/bcast.c
index 0d44025..bc1e5d6 100644
--- a/net/tipc/bcast.c
+++ b/net/tipc/bcast.c
@@ -537,6 +537,7 @@ receive:

 		buf = node->bclink.deferred_head;
 		node->bclink.deferred_head = buf->next;
+		buf->next = NULL;
 		node->bclink.deferred_size--;
 		goto receive;
 	}
--
1.9.1