diff options
| author | Eric Dumazet <edumazet@google.com> | 2021-09-03 15:03:43 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-09-22 12:28:05 +0200 |
| commit | 8c01c620ae61142760d8924ee96a3ff8eec00aa6 (patch) | |
| tree | 9ff9b00b18a90fffd8fce5669ec069c8f9854f23 /include/uapi/linux | |
| parent | 6e2d36f2b1d19bee1096a53e6cbc9e0c0f0b05b4 (diff) | |
fq_codel: reject silly quantum parameters
[ Upstream commit c7c5e6ff533fe1f9afef7d2fa46678987a1335a7 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'include/uapi/linux')
| -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 9e7c2c607845..69079fbf3ed2 100644 --- a/include/uapi/linux/pkt_sched.h +++ b/include/uapi/linux/pkt_sched.h @@ -826,6 +826,8 @@ struct tc_codel_xstats { /* FQ_CODEL */ +#define FQ_CODEL_QUANTUM_MAX (1 << 20) + enum { TCA_FQ_CODEL_UNSPEC, TCA_FQ_CODEL_TARGET, |