diff options
| author | Eric Dumazet <edumazet@google.com> | 2020-04-26 18:19:07 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2020-04-27 11:49:57 -0700 |
| commit | df4953e4e997e273501339f607b77953772e3559 (patch) | |
| tree | b6ebd6e34cfd0d4459e5f103f3b633f8cc1504f5 /net/sched/sch_sfq.c | |
| parent | cf7fc3af87b2d767f55eeec9faeb4b45b929341c (diff) | |
sch_sfq: validate silly quantum values
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>
Diffstat (limited to 'net/sched/sch_sfq.c')
| -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 c787d4d46017..5a6def5e4e6d 100644 --- a/net/sched/sch_sfq.c +++ b/net/sched/sch_sfq.c @@ -637,6 +637,15 @@ 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; |