[ 3.5.y.z extended stable ] Patch "isdn/gigaset: fix zero size border case in debug dump" has been added to staging queue

[Herton Ronaldo Krzesinski]

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

    isdn/gigaset: fix zero size border case in debug dump

to the linux-3.5.y-queue branch of the 3.5.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-3.5.y-queue

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

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Herton

------

>From c021525d8b2a8f9cf886cd8a706cdf351f5679ed Mon Sep 17 00:00:00 2001
From: Tilman Schmidt <tilman at imap.cc>
Date: Mon, 21 Jan 2013 11:57:21 +0000
Subject: [PATCH] isdn/gigaset: fix zero size border case in debug dump

commit d721a1752ba544df8d7d36959038b26bc92bdf80 upstream.

If subtracting 12 from l leaves zero we'd do a zero size allocation,
leading to an oops later when we try to set the NUL terminator.

Reported-by: Dan Carpenter <dan.carpenter at oracle.com>
Signed-off-by: Tilman Schmidt <tilman at imap.cc>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski at canonical.com>
---
 drivers/isdn/gigaset/capi.c |    2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/isdn/gigaset/capi.c b/drivers/isdn/gigaset/capi.c
index 27e4a3e..f45b5b0 100644
--- a/drivers/isdn/gigaset/capi.c
+++ b/drivers/isdn/gigaset/capi.c
@@ -248,6 +248,8 @@ static inline void dump_rawmsg(enum debuglevel level, const char *tag,
 		CAPIMSG_APPID(data), CAPIMSG_MSGID(data), l,
 		CAPIMSG_CONTROL(data));
 	l -= 12;
+	if (l <= 0)
+		return;
 	dbgline = kmalloc(3 * l, GFP_ATOMIC);
 	if (!dbgline)
 		return;
--
1.7.9.5