diff options
| author |   Cong Wang <cong.wang@bytedance.com> | 2025-02-03 16:58:40 -0800 |
|---|---|---|
| committer |   Jakub Kicinski <kuba@kernel.org> | 2025-02-05 18:14:46 -0800 |
| commit | 638ba5089324796c2ee49af10427459c2de35f71 (patch) | |
| tree | 1a044609bfa587a2a36d1010a0fe41eb0aa91d26 | |
| parent | selftests/tc-testing: Add a test case for pfifo_head_drop qdisc when limit==0 (diff) | |
| download | wireguard-linux-638ba5089324796c2ee49af10427459c2de35f71.tar.xz wireguard-linux-638ba5089324796c2ee49af10427459c2de35f71.zip | |
netem: Update sch->q.qlen before qdisc_tree_reduce_backlog()
qdisc_tree_reduce_backlog() notifies parent qdisc only if child
qdisc becomes empty, therefore we need to reduce the backlog of the
child qdisc before calling it. Otherwise it would miss the opportunity
to call cops->qlen_notify(), in the case of DRR, it resulted in UAF
since DRR uses ->qlen_notify() to maintain its active list.
Fixes: f8d4bc455047 ("net/sched: netem: account for backlog updates from child qdisc")
Cc: Martin Ottens <martin.ottens@fau.de>
Reported-by: Mingi Cho <mincho@theori.io>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Link: https://patch.msgid.link/20250204005841.223511-4-xiyou.wangcong@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | net/sched/sch_netem.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c index 71ec9986ed37..fdd79d3ccd8c 100644 --- a/net/sched/sch_netem.c +++ b/net/sched/sch_netem.c @@ -749,9 +749,9 @@ deliver: if (err != NET_XMIT_SUCCESS) { if (net_xmit_drop_count(err)) qdisc_qstats_drop(sch); - qdisc_tree_reduce_backlog(sch, 1, pkt_len); sch->qstats.backlog -= pkt_len; sch->q.qlen--; + qdisc_tree_reduce_backlog(sch, 1, pkt_len); } goto tfifo_dequeue; } |