Although we take RTNL on dump path, it is possible to
skip RTNL on insertion path. So the following race condition
is possible:
rtnl_lock() // no rtnl lock
mutex_lock(&idrinfo->lock);
// insert ERR_PTR(-EBUSY)
mutex_unlock(&idrinfo->lock);
tc_dump_action()
rtnl_unlock()
So we have to skip those temporary -EBUSY entries on dump path
too.
Reported-and-tested-by: [email protected]
Fixes: 0fedc63fadf0 ("net_sched: commit action insertions together")
Cc: Vlad Buslov <[email protected]>
Cc: Jamal Hadi Salim <[email protected]>
Cc: Jiri Pirko <[email protected]>
Signed-off-by: Cong Wang <[email protected]>
---
net/sched/act_api.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/net/sched/act_api.c b/net/sched/act_api.c
index 5612b336e18e..798430e1a79f 100644
--- a/net/sched/act_api.c
+++ b/net/sched/act_api.c
@@ -235,6 +235,8 @@ static int tcf_dump_walker(struct tcf_idrinfo *idrinfo,
struct sk_buff *skb,
index++;
if (index < s_i)
continue;
+ if (IS_ERR(p))
+ continue;
if (jiffy_since &&
time_after(jiffy_since,
--
2.28.0
