syzbot reported a crash in tc_act_in_hw() during netns teardown where tcf_idrinfo_destroy() passed an ERR_PTR(-EBUSY) value as a tc_action pointer, leading to an invalid dereference. Guard against ERR_PTR entries when iterating the action IDR so teardown does not call tc_act_in_hw() on an error pointer. Fixes: 84a7d6797e6a ("net/sched: acp_api: no longer acquire RTNL in tc_action_net_exit()") Link: https://syzkaller.appspot.com/bug?extid=8f1c492ffa4644ff3826 Reported-by: syzbot+8f1c492ffa4644ff3826@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=8f1c492ffa4644ff3826 Signed-off-by: Shivani Gupta --- v2: - Drop WARN_ON_ONCE() as ERR_PTR can be expected in a corner case. - Add Fixes: tag. net/sched/act_api.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/sched/act_api.c b/net/sched/act_api.c index ff6be5cfe2b0..5e0a196ce66a 100644 --- a/net/sched/act_api.c +++ b/net/sched/act_api.c @@ -940,6 +940,9 @@ void tcf_idrinfo_destroy(const struct tc_action_ops *ops, int ret; idr_for_each_entry_ul(idr, p, tmp, id) { + if (IS_ERR(p)) { + continue; + } if (tc_act_in_hw(p) && !mutex_taken) { rtnl_lock(); mutex_taken = true; -- 2.34.1