From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CD06870 for ; Thu, 1 Apr 2021 19:40:26 +0000 (UTC) IronPort-SDR: D9KH5b92xqRmXxtW0my3iFDISYBZp3bTw3ufz0wu2kIzuOWUYg+Bkf0HNISv3z5tuN2QZBgHl1 n0jKbaKesbAQ== X-IronPort-AV: E=McAfee;i="6000,8403,9941"; a="192422969" X-IronPort-AV: E=Sophos;i="5.81,296,1610438400"; d="scan'208";a="192422969" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Apr 2021 12:40:26 -0700 IronPort-SDR: BbUk/UUk2FFtIP8KlQygtPDobPNQPfoJNvKmaXy+KXux+aTaJ+Ajz5YlI8Ld6o1CaHs8HW7Z/x iCzuPMDwvGNg== X-IronPort-AV: E=Sophos;i="5.81,296,1610438400"; d="scan'208";a="419337883" Received: from jmurunue-mobl2.amr.corp.intel.com ([10.251.11.73]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Apr 2021 12:40:25 -0700 Date: Thu, 1 Apr 2021 12:40:25 -0700 (PDT) From: Mat Martineau To: Paolo Abeni cc: netdev@vger.kernel.org, mptcp@lists.linux.dev, "David S. Miller" , Jakub Kicinski Subject: Re: [PATCH net 1/2] mptcp: forbit mcast-related sockopt on MPTCP sockets In-Reply-To: Message-ID: <19889968-a3cb-61eb-1915-12c15133bf32@linux.intel.com> References: X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed 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 > --- > net/mptcp/protocol.c | 45 ++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 45 insertions(+) > Thanks Paolo. Reviewed-by: Mat Martineau -- Mat Martineau Intel