Re: [Cake] Patch "sch_cake: avoid possible divide by zero in cake_enqueue()" has been added to the 4.19-stable tree

[Dave Taht <dave.taht@gmail.com>]

did this make it into openwrt already?

On Sat, Jan 11, 2020 at 12:19 AM <gregkh@linuxfoundation.org> wrote:
>
>
> This is a note to let you know that I've just added the patch titled
>
>     sch_cake: avoid possible divide by zero in cake_enqueue()
>
> to the 4.19-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:
>      sch_cake-avoid-possible-divide-by-zero-in-cake_enqueue.patch
> and it can be found in the queue-4.19 subdirectory.
>
> If you, or anyone else, feels it should not be added to the stable tree,
> please let <stable@vger.kernel.org> know about it.
>
>
> From foo@baz Sat 11 Jan 2020 09:14:34 AM CET
> From: Wen Yang <wenyang@linux.alibaba.com>
> Date: Thu, 2 Jan 2020 17:21:43 +0800
> Subject: sch_cake: avoid possible divide by zero in cake_enqueue()
>
> From: Wen Yang <wenyang@linux.alibaba.com>
>
> [ Upstream commit 68aab823c223646fab311f8a6581994facee66a0 ]
>
> The variables 'window_interval' is u64 and do_div()
> truncates it to 32 bits, which means it can test
> non-zero and be truncated to zero for division.
> The unit of window_interval is nanoseconds,
> so its lower 32-bit is relatively easy to exceed.
> Fix this issue by using div64_u64() instead.
>
> Fixes: 7298de9cd725 ("sch_cake: Add ingress mode")
> Signed-off-by: Wen Yang <wenyang@linux.alibaba.com>
> Cc: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
> Cc: Toke Høiland-Jørgensen <toke@redhat.com>
> Cc: David S. Miller <davem@davemloft.net>
> Cc: Cong Wang <xiyou.wangcong@gmail.com>
> Cc: cake@lists.bufferbloat.net
> Cc: netdev@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Acked-by: Toke Høiland-Jørgensen <toke@toke.dk>
> Signed-off-by: David S. Miller <davem@davemloft.net>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> ---
>  net/sched/sch_cake.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> --- a/net/sched/sch_cake.c
> +++ b/net/sched/sch_cake.c
> @@ -1758,7 +1758,7 @@ static s32 cake_enqueue(struct sk_buff *
>                                                       q->avg_window_begin));
>                         u64 b = q->avg_window_bytes * (u64)NSEC_PER_SEC;
>
> -                       do_div(b, window_interval);
> +                       b = div64_u64(b, window_interval);
>                         q->avg_peak_bandwidth =
>                                 cake_ewma(q->avg_peak_bandwidth, b,
>                                           b > q->avg_peak_bandwidth ? 2 : 8);
>
>
> Patches currently in stable-queue which might be from wenyang@linux.alibaba.com are
>
> queue-4.19/sch_cake-avoid-possible-divide-by-zero-in-cake_enqueue.patch
> queue-4.19/regulator-fix-use-after-free-issue.patch
> _______________________________________________
> Cake mailing list
> Cake@lists.bufferbloat.net
> https://lists.bufferbloat.net/listinfo/cake



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Dave Täht
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