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| author | Vladimir Oltean <olteanv@gmail.com> | 2019-09-29 02:01:39 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-10-07 19:01:48 +0200 |
| commit | 0711307b9b65d13b38fb30e601d5a9f562066ccb (patch) | |
| tree | 28f520cc539b730ad769ba6f9df5015cc1d9a799 | |
| parent | 8dde3868b536a684d7ff5c2f9da9dd48bd71baa0 (diff) | |
| download | linux-stable-0711307b9b65d13b38fb30e601d5a9f562066ccb.tar.gz linux-stable-0711307b9b65d13b38fb30e601d5a9f562066ccb.tar.bz2 linux-stable-0711307b9b65d13b38fb30e601d5a9f562066ccb.zip | |
net: sched: taprio: Fix potential integer overflow in taprio_set_picos_per_byte
[ Upstream commit 68ce6688a5baefde30914fc07fc27292dbbe8320 ]
The speed divisor is used in a context expecting an s64, but it is
evaluated using 32-bit arithmetic.
To avoid that happening, instead of multiplying by 1,000,000 in the
first place, simplify the fraction and do a standard 32 bit division
instead.
Fixes: f04b514c0ce2 ("taprio: Set default link speed to 10 Mbps in taprio_set_picos_per_byte")
Reported-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Acked-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | net/sched/sch_taprio.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c index 8d8bc2ec5cd6..944b1af32156 100644 --- a/net/sched/sch_taprio.c +++ b/net/sched/sch_taprio.c @@ -965,8 +965,7 @@ static void taprio_set_picos_per_byte(struct net_device *dev, speed = ecmd.base.speed; skip: - picos_per_byte = div64_s64(NSEC_PER_SEC * 1000LL * 8, - speed * 1000 * 1000); + picos_per_byte = (USEC_PER_SEC * 8) / speed; atomic64_set(&q->picos_per_byte, picos_per_byte); netdev_dbg(dev, "taprio: set %s's picos_per_byte to: %lld, linkspeed: %d\n", |