diff options
| author | Eric Dumazet <edumazet@google.com> | 2021-09-04 01:03:43 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2021-09-04 12:49:46 +0300 |
| commit | c7c5e6ff533fe1f9afef7d2fa46678987a1335a7 (patch) | |
| tree | 73d9af6b6cc1fc846633747ce81c900a46e27960 /include/uapi | |
| parent | 10905b4a68cc58863e04d5ea5864323cb9341f9b (diff) | |
| download | linux-c7c5e6ff533fe1f9afef7d2fa46678987a1335a7.tar.xz | |
fq_codel: reject silly quantum parameters
syzbot found that forcing a big quantum attribute would crash hosts fast,
essentially using this:
tc qd replace dev eth0 root fq_codel quantum 4294967295
This is because fq_codel_dequeue() would have to loop
~2^31 times in :
if (flow->deficit <= 0) {
flow->deficit += q->quantum;
list_move_tail(&flow->flowchain, &q->old_flows);
goto begin;
}
SFQ max quantum is 2^19 (half a megabyte)
Lets adopt a max quantum of one megabyte for FQ_CODEL.
Fixes: 4b549a2ef4be ("fq_codel: Fair Queue Codel AQM")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/uapi')
| -rw-r--r-- | include/uapi/linux/pkt_sched.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/uapi/linux/pkt_sched.h b/include/uapi/linux/pkt_sched.h index 79a699f106b1..ec88590b3198 100644 --- a/include/uapi/linux/pkt_sched.h +++ b/include/uapi/linux/pkt_sched.h @@ -827,6 +827,8 @@ struct tc_codel_xstats { /* FQ_CODEL */ +#define FQ_CODEL_QUANTUM_MAX (1 << 20) + enum { TCA_FQ_CODEL_UNSPEC, TCA_FQ_CODEL_TARGET, |