From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from ganesha.gnumonks.org (ganesha.gnumonks.org [213.95.27.120]) (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 A9AE51E3DF0; Wed, 30 Oct 2024 12:02:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.95.27.120 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730289745; cv=none; b=XoBBLYX8vr7QjJF/WnxAGehoKKEOpJSmMHtqe2hoeNaaaHY0SMO3KJy+VcqwPpdVeVWceKzBJSERfhf3mevpqJoAPzjnTvnDgSi/7dj3VPSAxQd8CMqxpLDHxbR8WcyZjpNFy+DVnOxegt9HK+m0CtD251BQxMsNX35SqR83EMw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730289745; c=relaxed/simple; bh=X4PuOlu2OmPy5Pm8VWXenvbfCvduwpACca9+OC+pmJg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=QFhLI10UgJsscYW6p7Xk7iuYB+G+aEXD2GG2T1aTlcMm06ejTAebxVSqi5bFBNO2ch1ajKYOE+DISbnaV7aDjZZy6fb6kPhip3zM+PxmFMsMZQePozgAIwIdcZx8zX58tO0lLVXPhnELzsN8JbhlHgdajLPcwQQwek/l55GE/DM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=netfilter.org; spf=pass smtp.mailfrom=gnumonks.org; arc=none smtp.client-ip=213.95.27.120 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=netfilter.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gnumonks.org Received: from [78.30.37.63] (port=41894 helo=gnumonks.org) by ganesha.gnumonks.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1t67Ox-00BAA0-JW; Wed, 30 Oct 2024 13:02:18 +0100 Date: Wed, 30 Oct 2024 13:02:14 +0100 From: Pablo Neira Ayuso To: syzbot Cc: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, laforge@gnumonks.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, osmocom-net-gprs@lists.osmocom.org, pabeni@redhat.com, syzkaller-bugs@googlegroups.com, wenjia@linux.ibm.com, jaka@linux.ibm.com, alibuda@linux.alibaba.com, tonylu@linux.alibaba.com, guwen@linux.alibaba.com Subject: Re: [syzbot] [net?] possible deadlock in gtp_encap_enable_socket Message-ID: References: <66f18d50.050a0220.c23dd.0012.GAE@google.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <66f18d50.050a0220.c23dd.0012.GAE@google.com> X-Spam-Score: -1.7 (-) Cc'ing SMC maintainers. syzkaller combining layer is a crazy way to find crashes. I think this is a false possible lockdep considers smc->clcsock_release_lock is a lock of the same class sk_lock-AF_INET. this can be solved with lockdep_set_class in af_smc? Thanks. On Mon, Sep 23, 2024 at 08:46:24AM -0700, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: 9410645520e9 Merge tag 'net-next-6.12' of git://git.kernel.. > git tree: net-next > console+strace: https://syzkaller.appspot.com/x/log.txt?x=15d39e9f980000 > kernel config: https://syzkaller.appspot.com/x/.config?x=37c006d80708398d > dashboard link: https://syzkaller.appspot.com/bug?extid=e953a8f3071f5c0a28fd > compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16215ca9980000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=110c6c27980000 > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/80466d230dfb/disk-94106455.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/ba253eabab42/vmlinux-94106455.xz > kernel image: https://storage.googleapis.com/syzbot-assets/569982fb6c88/bzImage-94106455.xz > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+e953a8f3071f5c0a28fd@syzkaller.appspotmail.com > > IPVS: Unknown mcast interface: macvlan0 > netlink: 8 bytes leftover after parsing attributes in process `syz-executor297'. > netlink: 24 bytes leftover after parsing attributes in process `syz-executor297'. > ====================================================== > WARNING: possible circular locking dependency detected > 6.11.0-syzkaller-01458-g9410645520e9 #0 Not tainted > ------------------------------------------------------ > syz-executor297/5243 is trying to acquire lock: > ffff88801cf99158 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1609 [inline] > ffff88801cf99158 (sk_lock-AF_INET){+.+.}-{0:0}, at: gtp_encap_enable_socket+0x2ce/0x5c0 drivers/net/gtp.c:1674 > > but task is already holding lock: > ffffffff8fc88588 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] > ffffffff8fc88588 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6643 > > which lock already depends on the new lock. > > > the existing dependency chain (in reverse order) is: > > -> #2 (rtnl_mutex){+.+.}-{3:3}: > lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759 > __mutex_lock_common kernel/locking/mutex.c:608 [inline] > __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752 > start_sync_thread+0xdc/0x2dc0 net/netfilter/ipvs/ip_vs_sync.c:1761 > do_ip_vs_set_ctl+0x442/0x13d0 net/netfilter/ipvs/ip_vs_ctl.c:2732 > nf_setsockopt+0x295/0x2c0 net/netfilter/nf_sockopt.c:101 > smc_setsockopt+0x275/0xe50 net/smc/af_smc.c:3064 > do_sock_setsockopt+0x3af/0x720 net/socket.c:2330 > __sys_setsockopt+0x1ae/0x250 net/socket.c:2353 > __do_sys_setsockopt net/socket.c:2362 [inline] > __se_sys_setsockopt net/socket.c:2359 [inline] > __x64_sys_setsockopt+0xb5/0xd0 net/socket.c:2359 > do_syscall_x64 arch/x86/entry/common.c:52 [inline] > do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > > -> #1 (&smc->clcsock_release_lock){+.+.}-{3:3}: > lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759 > __mutex_lock_common kernel/locking/mutex.c:608 [inline] > __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752 > smc_switch_to_fallback+0x35/0xdb0 net/smc/af_smc.c:902 > smc_sendmsg+0x11f/0x530 net/smc/af_smc.c:2771 > sock_sendmsg_nosec net/socket.c:730 [inline] > __sock_sendmsg+0x221/0x270 net/socket.c:745 > ____sys_sendmsg+0x525/0x7d0 net/socket.c:2603 > ___sys_sendmsg net/socket.c:2657 [inline] > __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2686 > do_syscall_x64 arch/x86/entry/common.c:52 [inline] > do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > > -> #0 (sk_lock-AF_INET){+.+.}-{0:0}: > check_prev_add kernel/locking/lockdep.c:3133 [inline] > check_prevs_add kernel/locking/lockdep.c:3252 [inline] > validate_chain+0x18e0/0x5900 kernel/locking/lockdep.c:3868 > __lock_acquire+0x137a/0x2040 kernel/locking/lockdep.c:5142 > lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759 > lock_sock_nested+0x48/0x100 net/core/sock.c:3611 > lock_sock include/net/sock.h:1609 [inline] > gtp_encap_enable_socket+0x2ce/0x5c0 drivers/net/gtp.c:1674 > gtp_encap_enable drivers/net/gtp.c:1707 [inline] > gtp_newlink+0x589/0xf30 drivers/net/gtp.c:1511 > rtnl_newlink_create net/core/rtnetlink.c:3510 [inline] > __rtnl_newlink net/core/rtnetlink.c:3730 [inline] > rtnl_newlink+0x1591/0x20a0 net/core/rtnetlink.c:3743 > rtnetlink_rcv_msg+0x73f/0xcf0 net/core/rtnetlink.c:6646 > netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2550 > netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline] > netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1357 > netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1901 > sock_sendmsg_nosec net/socket.c:730 [inline] > __sock_sendmsg+0x221/0x270 net/socket.c:745 > ____sys_sendmsg+0x525/0x7d0 net/socket.c:2603 > ___sys_sendmsg net/socket.c:2657 [inline] > __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2686 > do_syscall_x64 arch/x86/entry/common.c:52 [inline] > do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > > other info that might help us debug this: > > Chain exists of: > sk_lock-AF_INET --> &smc->clcsock_release_lock --> rtnl_mutex > > Possible unsafe locking scenario: > > CPU0 CPU1 > ---- ---- > lock(rtnl_mutex); > lock(&smc->clcsock_release_lock); > lock(rtnl_mutex); > lock(sk_lock-AF_INET); > > *** DEADLOCK *** > > 1 lock held by syz-executor297/5243: > #0: ffffffff8fc88588 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] > #0: ffffffff8fc88588 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6643 > > stack backtrace: > CPU: 0 UID: 0 PID: 5243 Comm: syz-executor297 Not tainted 6.11.0-syzkaller-01458-g9410645520e9 #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 > Call Trace: > > __dump_stack lib/dump_stack.c:93 [inline] > dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119 > check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2186 > check_prev_add kernel/locking/lockdep.c:3133 [inline] > check_prevs_add kernel/locking/lockdep.c:3252 [inline] > validate_chain+0x18e0/0x5900 kernel/locking/lockdep.c:3868 > __lock_acquire+0x137a/0x2040 kernel/locking/lockdep.c:5142 > lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759 > lock_sock_nested+0x48/0x100 net/core/sock.c:3611 > lock_sock include/net/sock.h:1609 [inline] > gtp_encap_enable_socket+0x2ce/0x5c0 drivers/net/gtp.c:1674 > gtp_encap_enable drivers/net/gtp.c:1707 [inline] > gtp_newlink+0x589/0xf30 drivers/net/gtp.c:1511 > rtnl_newlink_create net/core/rtnetlink.c:3510 [inline] > __rtnl_newlink net/core/rtnetlink.c:3730 [inline] > rtnl_newlink+0x1591/0x20a0 net/core/rtnetlink.c:3743 > rtnetlink_rcv_msg+0x73f/0xcf0 net/core/rtnetlink.c:6646 > netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2550 > netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline] > netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1357 > netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1901 > sock_sendmsg_nosec net/socket.c:730 [inline] > __sock_sendmsg+0x221/0x270 net/socket.c:745 > ____sys_sendmsg+0x525/0x7d0 net/socket.c:2603 > ___sys_sendmsg net/socket.c:2657 [inline] > __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2686 > do_syscall_x64 arch/x86/entry/common.c:52 [inline] > do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > RIP: 0033:0x7fed198844a9 > Code: 48 83 c4 28 c3 e8 37 17 00 00 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 > RS > > > --- > This report is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller@googlegroups.com. > > syzbot will keep track of this issue. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > > If the report is already addressed, let syzbot know by replying with: > #syz fix: exact-commit-title > > If you want syzbot to run the reproducer, reply with: > #syz test: git://repo/address.git branch-or-commit-hash > If you attach or paste a git patch, syzbot will apply it before testing. > > If you want to overwrite report's subsystems, reply with: > #syz set subsystems: new-subsystem > (See the list of subsystem names on the web dashboard) > > If the report is a duplicate of another one, reply with: > #syz dup: exact-subject-of-another-report > > If you want to undo deduplication, reply with: > #syz undup