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| author | Eric Dumazet <edumazet@google.com> | 2020-04-26 18:19:07 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-05-20 08:16:54 +0200 |
| commit | 9945949908fe11b27fa1127d2fc9e3182c218312 (patch) | |
| tree | dd97567adc006150ff70cd94df49c88237def7e7 | |
| parent | 4836eb6b59657a383fa97d3d301da77581ec8f0c (diff) | |
| download | linux-stable-9945949908fe11b27fa1127d2fc9e3182c218312.tar.gz linux-stable-9945949908fe11b27fa1127d2fc9e3182c218312.tar.bz2 linux-stable-9945949908fe11b27fa1127d2fc9e3182c218312.zip | |
sch_sfq: validate silly quantum values
[ Upstream commit df4953e4e997e273501339f607b77953772e3559 ]
syzbot managed to set up sfq so that q->scaled_quantum was zero,
triggering an infinite loop in sfq_dequeue()
More generally, we must only accept quantum between 1 and 2^18 - 7,
meaning scaled_quantum must be in [1, 0x7FFF] range.
Otherwise, we also could have a loop in sfq_dequeue()
if scaled_quantum happens to be 0x8000, since slot->allot
could indefinitely switch between 0 and 0x8000.
Fixes: eeaeb068f139 ("sch_sfq: allow big packets and be fair")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot+0251e883fe39e7a0cb0a@syzkaller.appspotmail.com
Cc: Jason A. Donenfeld <Jason@zx2c4.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_sfq.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/net/sched/sch_sfq.c b/net/sched/sch_sfq.c index cbc54ddfe076..1eae4de319b3 100644 --- a/net/sched/sch_sfq.c +++ b/net/sched/sch_sfq.c @@ -639,6 +639,15 @@ static int sfq_change(struct Qdisc *sch, struct nlattr *opt) if (ctl->divisor && (!is_power_of_2(ctl->divisor) || ctl->divisor > 65536)) return -EINVAL; + + /* slot->allot is a short, make sure quantum is not too big. */ + if (ctl->quantum) { + unsigned int scaled = SFQ_ALLOT_SIZE(ctl->quantum); + + if (scaled <= 0 || scaled > SHRT_MAX) + return -EINVAL; + } + if (ctl_v1 && !red_check_params(ctl_v1->qth_min, ctl_v1->qth_max, ctl_v1->Wlog)) return -EINVAL; |