This is a note to let you know that I've just added the patch titled
pkt_sched: fix virtual-start-time update in QFQ
to the 3.5-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
pkt_sched-fix-virtual-start-time-update-in-qfq.patch
and it can be found in the queue-3.5 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From e985d11c858cc02bc0d61c23f3439f9b842fd6c6 Mon Sep 17 00:00:00 2001
From: Paolo Valente <[email protected]>
Date: Sat, 15 Sep 2012 00:41:35 +0000
Subject: pkt_sched: fix virtual-start-time update in QFQ
From: Paolo Valente <[email protected]>
[ Upstream commit 71261956973ba9e0637848a5adb4a5819b4bae83 ]
If the old timestamps of a class, say cl, are stale when the class
becomes active, then QFQ may assign to cl a much higher start time
than the maximum value allowed. This may happen when QFQ assigns to
the start time of cl the finish time of a group whose classes are
characterized by a higher value of the ratio
max_class_pkt/weight_of_the_class with respect to that of
cl. Inserting a class with a too high start time into the bucket list
corrupts the data structure and may eventually lead to crashes.
This patch limits the maximum start time assigned to a class.
Signed-off-by: Paolo Valente <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
net/sched/sch_qfq.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
--- a/net/sched/sch_qfq.c
+++ b/net/sched/sch_qfq.c
@@ -831,7 +831,10 @@ static void qfq_update_start(struct qfq_
if (mask) {
struct qfq_group *next = qfq_ffs(q, mask);
if (qfq_gt(roundedF, next->F)) {
- cl->S = next->F;
+ if (qfq_gt(limit, next->F))
+ cl->S = next->F;
+ else /* preserve timestamp correctness */
+ cl->S = limit;
return;
}
}
Patches currently in stable-queue which might be from [email protected]
are
queue-3.5/pkt_sched-fix-virtual-start-time-update-in-qfq.patch
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