summaryrefslogtreecommitdiff
path: root/net
diff options
context:
space:
mode:
authorEric Dumazet <edumazet@google.com>2020-01-06 17:10:39 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-01-12 14:12:06 +0300
commit73a6f18d8390abc233212085ba4f06088f9fb075 (patch)
tree6a0bc2ba28e6867556beca903e939e284e069ade /net
parenta45335027cece5e979c1bb1a603604b2f34f32f8 (diff)
downloadlinux-73a6f18d8390abc233212085ba4f06088f9fb075.tar.xz
pkt_sched: fq: do not accept silly TCA_FQ_QUANTUM
[ Upstream commit d9e15a2733067c9328fb56d98fe8e574fa19ec31 ] As diagnosed by Florian : If TCA_FQ_QUANTUM is set to 0x80000000, fq_deueue() can loop forever in : if (f->credit <= 0) { f->credit += q->quantum; goto begin; } ... because f->credit is either 0 or -2147483648. Let's limit TCA_FQ_QUANTUM to no more than 1 << 20 : This max value should limit risks of breaking user setups while fixing this bug. Fixes: afe4fd062416 ("pkt_sched: fq: Fair Queue packet scheduler") Signed-off-by: Eric Dumazet <edumazet@google.com> Diagnosed-by: Florian Westphal <fw@strlen.de> Reported-by: syzbot+dc9071cc5a85950bdfce@syzkaller.appspotmail.com Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net')
-rw-r--r--net/sched/sch_fq.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/net/sched/sch_fq.c b/net/sched/sch_fq.c
index f50eb87cfe79..7a944f508cae 100644
--- a/net/sched/sch_fq.c
+++ b/net/sched/sch_fq.c
@@ -734,7 +734,7 @@ static int fq_change(struct Qdisc *sch, struct nlattr *opt)
if (tb[TCA_FQ_QUANTUM]) {
u32 quantum = nla_get_u32(tb[TCA_FQ_QUANTUM]);
- if (quantum > 0)
+ if (quantum > 0 && quantum <= (1 << 20))
q->quantum = quantum;
else
err = -EINVAL;