From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-il1-f205.google.com (mail-il1-f205.google.com [209.85.166.205]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 91FC72E6112 for ; Tue, 24 Jun 2025 18:51:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.205 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750791092; cv=none; b=NWPiiEoJwgntkF2ZN8ToLemVID2ZcnR9RuRKRH3NcyUTbf5s9B2lkMF+9+5/eG2Q+00UyCupGzyItXHE78fSlpQPS6VJ5xG+eNA5BUXlTJbQQKMpD4S1CVbI/PTALoKcAWKRjCrbLeaJat6urTifTsikg0MCkqHmxbvMvYbEZ78= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750791092; c=relaxed/simple; bh=K+1ubdXTQvJ3y7AP8pyMgWti8Z2MztgkeevuOPDWK7Q=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=GFoHYLXRZjlYPZj8f9SbvrqJ+qU6VFMSeaSM0XjV7qlWu3fHvZmg5msrloUrX0JgnYaPF2cX37XYtNd6vpjLjRB5eyOBZzlsYvYfSx5wmFGYsW1BRimpY2zMwooPlB/lKV5DeXIbp2qky063Hlt8tDeL1PuSC1xA8CG+9tESHUU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=209.85.166.205 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-il1-f205.google.com with SMTP id e9e14a558f8ab-3ddbec809acso11908515ab.2 for ; Tue, 24 Jun 2025 11:51:30 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1750791090; x=1751395890; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=KptIPdLrONVssSAfLQ4Jd3RDXJtiQLHPC5AKkVycC08=; b=QiwlaPdHdt7UFL9wSFaG96ycoRVGxZObFBySdPZZ/FIoU4Jldlmv1x9KxDXL00zP3g QUEeZT9xX5wXeplI6C6Xil7poj1uls1jTby72unKBI2b8NGJCf7WofzQVaGclL8NBS4L 5J3BJLJxbakuGSugkNCgGtU0RRnJ4k8olC0mgfepHuLWLvEv+xBNTW21RbeRmOnNzndX iTvESeFskcGyFXrNtlGsc6FDzARYRkm4XZ/s5oocusxMqzshFgvRpnhwg5dcwXEOkXqg qr6dgb9wAXPZB6ipUL0IrV1R3QpabSU1Umxqe/LDfktZxPRJZ9itRaWCSdIyHE05s5tP ccoA== X-Forwarded-Encrypted: i=1; AJvYcCUqb5YvSePJd16Ykann1WfXkGRmReZFPqyibmupOnPfUSa3WpW04YJ+9Tcnp4lazs+4sMHDYRI=@vger.kernel.org X-Gm-Message-State: AOJu0Yy3Ll7/GaGer4faogYJ3Lm5TEfYoiUB/tBQLatsWlylB7JoQkKy ckf0YA3J/sV82FpUZlmUal20+vCskqb49MJVdpPNH2qdUjGhL3KWIDM74jIK64Vv8ff8kBX/c+P 4+TK3OCB4w5XK0LLkKV8PYF5TJ0JBpMl3253RUyBY4UQ9TAmx999pYetNVO0= X-Google-Smtp-Source: AGHT+IE4YdoGq7Ae0oz3CX3vyyyJmEpp8RB0che9Wat6YMFbWJOPBPupBOUPqHTivhf48uwLkz6o7KUrZn5oCyb/fq9npnT2MxmS Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6e02:b26:b0:3dd:d155:94cb with SMTP id e9e14a558f8ab-3df328f8928mr2266875ab.7.1750791089663; Tue, 24 Jun 2025 11:51:29 -0700 (PDT) Date: Tue, 24 Jun 2025 11:51:29 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <685af3b1.a00a0220.2e5631.0091.GAE@google.com> Subject: [syzbot] [bpf?] [net?] possible deadlock in xsk_notifier (3) From: syzbot To: andrii@kernel.org, ast@kernel.org, bjorn@kernel.org, bpf@vger.kernel.org, daniel@iogearbox.net, davem@davemloft.net, edumazet@google.com, horms@kernel.org, jonathan.lemon@gmail.com, kuba@kernel.org, linux-kernel@vger.kernel.org, maciej.fijalkowski@intel.com, magnus.karlsson@intel.com, netdev@vger.kernel.org, pabeni@redhat.com, sdf@fomichev.me, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 78f4e737a53e Merge tag 'for-6.16/dm-fixes' of git://git.ke.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=11b48f0c580000 kernel config: https://syzkaller.appspot.com/x/.config?x=12ec1a20ad573841 dashboard link: https://syzkaller.appspot.com/bug?extid=e67ea9c235b13b4f0020 compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/3ff97b2d201b/disk-78f4e737.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/1968f46c8915/vmlinux-78f4e737.xz kernel image: https://storage.googleapis.com/syzbot-assets/3455e371b965/bzImage-78f4e737.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+e67ea9c235b13b4f0020@syzkaller.appspotmail.com netlink: 4 bytes leftover after parsing attributes in process `syz.1.1331'. ====================================================== WARNING: possible circular locking dependency detected 6.16.0-rc3-syzkaller-00042-g78f4e737a53e #0 Not tainted ------------------------------------------------------ syz.1.1331/11144 is trying to acquire lock: ffff888054b136b0 (&xs->mutex){+.+.}-{4:4}, at: xsk_notifier+0x101/0x280 net/xdp/xsk.c:1649 but task is already holding lock: ffff888052f43d58 (&net->xdp.lock){+.+.}-{4:4}, at: xsk_notifier+0xa4/0x280 net/xdp/xsk.c:1645 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&net->xdp.lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:602 [inline] __mutex_lock+0x199/0xb90 kernel/locking/mutex.c:747 xsk_notifier+0xa4/0x280 net/xdp/xsk.c:1645 notifier_call_chain+0xbc/0x410 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2230 call_netdevice_notifiers_extack net/core/dev.c:2268 [inline] call_netdevice_notifiers net/core/dev.c:2282 [inline] unregister_netdevice_many_notify+0xf9d/0x2700 net/core/dev.c:12077 unregister_netdevice_many net/core/dev.c:12140 [inline] unregister_netdevice_queue+0x305/0x3f0 net/core/dev.c:11984 register_netdevice+0x18f1/0x2270 net/core/dev.c:11149 lapbeth_new_device drivers/net/wan/lapbether.c:420 [inline] lapbeth_device_event+0x5b1/0xbe0 drivers/net/wan/lapbether.c:462 notifier_call_chain+0xbc/0x410 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2230 call_netdevice_notifiers_extack net/core/dev.c:2268 [inline] call_netdevice_notifiers net/core/dev.c:2282 [inline] __dev_notify_flags+0x12c/0x2e0 net/core/dev.c:9497 netif_change_flags+0x108/0x160 net/core/dev.c:9526 dev_change_flags+0xba/0x250 net/core/dev_api.c:68 devinet_ioctl+0x11d5/0x1f50 net/ipv4/devinet.c:1200 inet_ioctl+0x3a7/0x3f0 net/ipv4/af_inet.c:1001 sock_do_ioctl+0x118/0x280 net/socket.c:1190 sock_ioctl+0x227/0x6b0 net/socket.c:1311 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl fs/ioctl.c:893 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&dev_instance_lock_key#20){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:602 [inline] __mutex_lock+0x199/0xb90 kernel/locking/mutex.c:747 netdev_lock include/linux/netdevice.h:2756 [inline] netdev_lock_ops include/net/netdev_lock.h:42 [inline] xsk_bind+0x37c/0x1570 net/xdp/xsk.c:1189 __sys_bind_socket net/socket.c:1810 [inline] __sys_bind_socket net/socket.c:1802 [inline] __sys_bind+0x1a7/0x260 net/socket.c:1841 __do_sys_bind net/socket.c:1846 [inline] __se_sys_bind net/socket.c:1844 [inline] __x64_sys_bind+0x72/0xb0 net/socket.c:1844 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&xs->mutex){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3168 [inline] check_prevs_add kernel/locking/lockdep.c:3287 [inline] validate_chain kernel/locking/lockdep.c:3911 [inline] __lock_acquire+0x126f/0x1c90 kernel/locking/lockdep.c:5240 lock_acquire kernel/locking/lockdep.c:5871 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5828 __mutex_lock_common kernel/locking/mutex.c:602 [inline] __mutex_lock+0x199/0xb90 kernel/locking/mutex.c:747 xsk_notifier+0x101/0x280 net/xdp/xsk.c:1649 notifier_call_chain+0xbc/0x410 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2230 call_netdevice_notifiers_extack net/core/dev.c:2268 [inline] call_netdevice_notifiers net/core/dev.c:2282 [inline] unregister_netdevice_many_notify+0xf9d/0x2700 net/core/dev.c:12077 rtnl_delete_link net/core/rtnetlink.c:3511 [inline] rtnl_dellink+0x3cb/0xa80 net/core/rtnetlink.c:3553 rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:6944 netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2534 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] netlink_unicast+0x53d/0x7f0 net/netlink/af_netlink.c:1339 netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1883 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg net/socket.c:727 [inline] ____sys_sendmsg+0xa98/0xc70 net/socket.c:2566 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2620 __sys_sendmsg+0x16d/0x220 net/socket.c:2652 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: &xs->mutex --> &dev_instance_lock_key#20 --> &net->xdp.lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&net->xdp.lock); lock(&dev_instance_lock_key#20); lock(&net->xdp.lock); lock(&xs->mutex); *** DEADLOCK *** 2 locks held by syz.1.1331/11144: #0: ffffffff9034e4a8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff9034e4a8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff9034e4a8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dellink+0x277/0xa80 net/core/rtnetlink.c:3545 #1: ffff888052f43d58 (&net->xdp.lock){+.+.}-{4:4}, at: xsk_notifier+0xa4/0x280 net/xdp/xsk.c:1645 stack backtrace: CPU: 1 UID: 0 PID: 11144 Comm: syz.1.1331 Not tainted 6.16.0-rc3-syzkaller-00042-g78f4e737a53e #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_circular_bug+0x275/0x350 kernel/locking/lockdep.c:2046 check_noncircular+0x14c/0x170 kernel/locking/lockdep.c:2178 check_prev_add kernel/locking/lockdep.c:3168 [inline] check_prevs_add kernel/locking/lockdep.c:3287 [inline] validate_chain kernel/locking/lockdep.c:3911 [inline] __lock_acquire+0x126f/0x1c90 kernel/locking/lockdep.c:5240 lock_acquire kernel/locking/lockdep.c:5871 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5828 __mutex_lock_common kernel/locking/mutex.c:602 [inline] __mutex_lock+0x199/0xb90 kernel/locking/mutex.c:747 xsk_notifier+0x101/0x280 net/xdp/xsk.c:1649 notifier_call_chain+0xbc/0x410 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2230 call_netdevice_notifiers_extack net/core/dev.c:2268 [inline] call_netdevice_notifiers net/core/dev.c:2282 [inline] unregister_netdevice_many_notify+0xf9d/0x2700 net/core/dev.c:12077 rtnl_delete_link net/core/rtnetlink.c:3511 [inline] rtnl_dellink+0x3cb/0xa80 net/core/rtnetlink.c:3553 rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:6944 netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2534 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] netlink_unicast+0x53d/0x7f0 net/netlink/af_netlink.c:1339 netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1883 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg net/socket.c:727 [inline] ____sys_sendmsg+0xa98/0xc70 net/socket.c:2566 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2620 __sys_sendmsg+0x16d/0x220 net/socket.c:2652 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f97c7b8e929 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f97c8abc038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f97c7db5fa0 RCX: 00007f97c7b8e929 RDX: 0000000000000000 RSI: 0000200000000040 RDI: 0000000000000003 RBP: 00007f97c7c10b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f97c7db5fa0 R15: 00007fff09d1ae48 batman_adv: batadv0: Removing interface: batadv_slave_1 --- 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 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