[ 3.8.y.z extended stable ] Patch "htb: fix sign extension bug" has been added to staging queue

Kamal Mostafa kamal at canonical.com
Tue Oct 1 16:24:05 UTC 2013


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

    htb: fix sign extension bug

to the linux-3.8.y-queue branch of the 3.8.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-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.11.

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

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 72367a2fb01545cbc5a5d07ac5048459c5ff80f6 Mon Sep 17 00:00:00 2001
From: stephen hemminger <stephen at networkplumber.org>
Date: Thu, 1 Aug 2013 22:32:07 -0700
Subject: htb: fix sign extension bug

[ Upstream commit cbd375567f7e4811b1c721f75ec519828ac6583f ]

When userspace passes a large priority value
the assignment of the unsigned value hopt->prio
to  signed int cl->prio causes cl->prio to become negative and the
comparison is with TC_HTB_NUMPRIO is always false.

The result is that HTB crashes by referencing outside
the array when processing packets. With this patch the large value
wraps around like other values outside the normal range.

See: https://bugzilla.kernel.org/show_bug.cgi?id=60669

Signed-off-by: Stephen Hemminger <stephen at networkplumber.org>
Acked-by: Eric Dumazet <edumazet at google.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 net/sched/sch_htb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c
index 79e8ed4..8ea8a79 100644
--- a/net/sched/sch_htb.c
+++ b/net/sched/sch_htb.c
@@ -92,7 +92,7 @@ struct htb_class {
 	unsigned int children;
 	struct htb_class *parent;	/* parent class */

-	int prio;		/* these two are used only by leaves... */
+	u32 prio;		/* these two are used only by leaves... */
 	int quantum;		/* but stored for parent-to-leaf return */

 	union {
--
1.8.1.2





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