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| author |   Wen Yang <wenyang@linux.alibaba.com> | 2020-01-02 17:21:43 +0800 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2020-01-02 16:34:28 -0800 |
| commit | 68aab823c223646fab311f8a6581994facee66a0 (patch) | |
| tree | b0ca5b68fbeda17f190305cdae73670591f7887a /net/sched/sch_cake.c | |
| parent | net: Correct type of tcp_syncookies sysctl. (diff) | |
| download | linux-dev-68aab823c223646fab311f8a6581994facee66a0.tar.xz linux-dev-68aab823c223646fab311f8a6581994facee66a0.zip | |
sch_cake: avoid possible divide by zero in cake_enqueue()
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>
Diffstat (limited to 'net/sched/sch_cake.c')
| -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 e0f40400f679..2277369feae5 100644 --- a/net/sched/sch_cake.c +++ b/net/sched/sch_cake.c @@ -1769,7 +1769,7 @@ 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); |