On Thu, 1 Apr 2021, Paolo Abeni wrote:
Unrolling mcast state at msk dismantel time is bug prone, as syzkaller reported:====================================================== WARNING: possible circular locking dependency detected 5.11.0-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor905/8822 is trying to acquire lock: ffffffff8d678fe8 (rtnl_mutex){+.+.}-{3:3}, at: ipv6_sock_mc_close+0xd7/0x110 net/ipv6/mcast.c:323 but task is already holding lock: ffff888024390120 (sk_lock-AF_INET6){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1600 [inline] ffff888024390120 (sk_lock-AF_INET6){+.+.}-{0:0}, at: mptcp6_release+0x57/0x130 net/mptcp/protocol.c:3507 which lock already depends on the new lock. Instead we can simply forbit any mcast-related setsockopt Fixes: 717e79c867ca5 ("mptcp: Add setsockopt()/getsockopt() socket operations") Signed-off-by: Paolo Abeni <pab...@redhat.com> --- net/mptcp/protocol.c | 45 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+)
Thanks Paolo. Reviewed-by: Mat Martineau <mathew.j.martin...@linux.intel.com> -- Mat Martineau Intel
