diff options
author | Wen Yang <wenyang@linux.alibaba.com> | 2020-01-02 17:21:43 +0800 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-01-12 12:17:26 +0100 |
commit | f5c8c211d811b0e0b705f66b36ad2de11e71aef0 (patch) | |
tree | fa1e7b7185cd3acee03ee63b7bba5035912d0aee /net/sched | |
parent | 94ac4a4d938f51a18a51286fd94a46c1d6558103 (diff) |
sch_cake: avoid possible divide by zero in cake_enqueue()
[ 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>
Diffstat (limited to 'net/sched')
-rw-r--r-- | net/sched/sch_cake.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c index e4cf72b0675e..824e3c37e5dd 100644 --- a/net/sched/sch_cake.c +++ b/net/sched/sch_cake.c @@ -1758,7 +1758,7 @@ static s32 cake_enqueue(struct sk_buff *skb, struct Qdisc *sch, 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); |