diff options
| author | Davide Caratti <dcaratti@redhat.com> | 2023-04-20 16:59:46 +0200 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2023-04-21 20:24:29 -0700 |
| commit | 7041101ff6c3073fd8f2e99920f535b111c929cb (patch) | |
| tree | 1c1b6f7d442e35aa823ce1b53372f4f6472a16b1 /net/sched | |
| parent | 63cfd210034c772fad047afa13dd5a4664b0a72e (diff) | |
| download | linux-7041101ff6c3073fd8f2e99920f535b111c929cb.tar.gz | |
net/sched: sch_fq: fix integer overflow of "credit"
if sch_fq is configured with "initial quantum" having values greater than
INT_MAX, the first assignment of "credit" does signed integer overflow to
a very negative value.
In this situation, the syzkaller script provided by Cristoph triggers the
CPU soft-lockup warning even with few sockets. It's not an infinite loop,
but "credit" wasn't probably meant to be minus 2Gb for each new flow.
Capping "initial quantum" to INT_MAX proved to fix the issue.
v2: validation of "initial quantum" is done in fq_policy, instead of open
coding in fq_change() _ suggested by Jakub Kicinski
Reported-by: Christoph Paasch <cpaasch@apple.com>
Link: https://github.com/multipath-tcp/mptcp_net-next/issues/377
Fixes: afe4fd062416 ("pkt_sched: fq: Fair Queue packet scheduler")
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Link: https://lore.kernel.org/r/7b3a3c7e36d03068707a021760a194a8eb5ad41a.1682002300.git.dcaratti@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/sched')
| -rw-r--r-- | net/sched/sch_fq.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/net/sched/sch_fq.c b/net/sched/sch_fq.c index 48d14fb90ba02..f59a2cb2c803d 100644 --- a/net/sched/sch_fq.c +++ b/net/sched/sch_fq.c @@ -779,13 +779,17 @@ static int fq_resize(struct Qdisc *sch, u32 log) return 0; } +static struct netlink_range_validation iq_range = { + .max = INT_MAX, +}; + static const struct nla_policy fq_policy[TCA_FQ_MAX + 1] = { [TCA_FQ_UNSPEC] = { .strict_start_type = TCA_FQ_TIMER_SLACK }, [TCA_FQ_PLIMIT] = { .type = NLA_U32 }, [TCA_FQ_FLOW_PLIMIT] = { .type = NLA_U32 }, [TCA_FQ_QUANTUM] = { .type = NLA_U32 }, - [TCA_FQ_INITIAL_QUANTUM] = { .type = NLA_U32 }, + [TCA_FQ_INITIAL_QUANTUM] = NLA_POLICY_FULL_RANGE(NLA_U32, &iq_range), [TCA_FQ_RATE_ENABLE] = { .type = NLA_U32 }, [TCA_FQ_FLOW_DEFAULT_RATE] = { .type = NLA_U32 }, [TCA_FQ_FLOW_MAX_RATE] = { .type = NLA_U32 }, |