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authorCong Wang <xiyou.wangcong@gmail.com>2020-10-02 12:13:34 -0700
committerDavid S. Miller <davem@davemloft.net>2020-10-04 14:53:06 -0700
commit580e4273d7a883ececfefa692c1f96bdbacb99b5 (patch)
tree094b0f1cde71ff222877ed9f94175f474c387696
parent9a9e77495958c7382b2438bc19746dd3aaaabb8e (diff)
downloadlinux-580e4273d7a883ececfefa692c1f96bdbacb99b5.tar.bz2
net_sched: check error pointer in tcf_dump_walker()
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: syzbot+b47bc4f247856fb4d9e1@syzkaller.appspotmail.com Fixes: 0fedc63fadf0 ("net_sched: commit action insertions together") Cc: Vlad Buslov <vladbu@mellanox.com> Cc: Jamal Hadi Salim <jhs@mojatatu.com> Cc: Jiri Pirko <jiri@resnulli.us> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/sched/act_api.c2
1 files changed, 2 insertions, 0 deletions
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,