diff options
| author | Dmitry Antipov <[email protected]> | 2024-10-18 08:13:38 +0300 |
|---|---|---|
| committer | Paolo Abeni <[email protected]> | 2024-10-23 13:26:15 +0200 |
| commit | f504465970aebb2467da548f7c1efbbf36d0f44b (patch) | |
| tree | 65d1669c2f612b7be7286e8f99d8658ef39edc7d | |
| parent | 34d35b4edbbe890a91bec939bfd29ad92517a52b (diff) | |
net: sched: fix use-after-free in taprio_change()
In 'taprio_change()', 'admin' pointer may become dangling due to sched
switch / removal caused by 'advance_sched()', and critical section
protected by 'q->current_entry_lock' is too small to prevent from such
a scenario (which causes use-after-free detected by KASAN). Fix this
by prefer 'rcu_replace_pointer()' over 'rcu_assign_pointer()' to update
'admin' immediately before an attempt to schedule freeing.
Fixes: a3d43c0d56f1 ("taprio: Add support adding an admin schedule")
Reported-by: [email protected]
Closes: https://syzkaller.appspot.com/bug?extid=b65e0af58423fc8a73aa
Acked-by: Vinicius Costa Gomes <[email protected]>
Signed-off-by: Dmitry Antipov <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>
| -rw-r--r-- | net/sched/sch_taprio.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c index 8498d0606b24..9f4e004cdb8b 100644 --- a/net/sched/sch_taprio.c +++ b/net/sched/sch_taprio.c @@ -1965,7 +1965,8 @@ static int taprio_change(struct Qdisc *sch, struct nlattr *opt, taprio_start_sched(sch, start, new_admin); - rcu_assign_pointer(q->admin_sched, new_admin); + admin = rcu_replace_pointer(q->admin_sched, new_admin, + lockdep_rtnl_is_held()); if (admin) call_rcu(&admin->rcu, taprio_free_sched_cb); |