Baozeng reported this deadlock case:
CPU0 CPU1
---- ----
lock([ 165.136033] sk_lock-AF_INET6);
lock([ 165.136033] rtnl_mutex);
lock([ 165.136033] sk_lock-AF_INET6);
lock([ 165.136033] rtnl_mutex);
Similar to commit 87e9f0315952
("ipv4: fix a potential deadlock in mcast getsockopt() path")
this is due to we still have a case, ipv6_sock_mc_close(),
where we acquire sk_lock before rtnl_lock. Close this deadlock
with the similar solution, that is always acquire rtnl lock first.
Fixes: baf606d9c9b1 ("ipv4,ipv6: grab rtnl before locking the socket")
Reported-by: Baozeng Ding <sploving1@gmail.com>
Tested-by: Baozeng Ding <sploving1@gmail.com>
Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8651be8f14