From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo1-f78.google.com (mail-oo1-f78.google.com [209.85.161.78]) (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 A72FE36655C for ; Mon, 15 Jun 2026 07:28:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.161.78 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781508520; cv=none; b=qstjrL3ZvHrmaZTCBrmoCIOc6rW+q0OpWzPSYPDwol2FeWJZaDjg0PIaUlz1tQjdsM9A7WhjJK3g9gTHdfQRYdioH6/8bphtWV+PhMz0wbBEJItd71MFLT436aIutemoi9LJiw8t2LNKc8j+m+6ANLuPGHd3HaCBe8vZ1RMxI+Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781508520; c=relaxed/simple; bh=8lpEyypN30gWNikBRixhQnFqfMFEC+3s1f9GVjm67GU=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=Z+QYUYTdotxt4B1jlubO5vqz+7brG2iqVisfBzgygt5zwOXa4HxNRnxpAtolqwEPolWcChieqq3dbGP6Su/ZZTkVyRD6jI2/ngbNZ2Mrn3rNBTVjTqiTIoHHqqr/rucNfpycPQxjyrEVObBO3lUqoHejnET8+6SFbFkVQ8+RWNM= 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=209.85.161.78 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-oo1-f78.google.com with SMTP id 006d021491bc7-69de11bef3dso4380206eaf.0 for ; Mon, 15 Jun 2026 00:28:38 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1781508517; x=1782113317; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=E3z+zv4CdVXSRoO/fwCBnamP3Uf88pmxkrNhNxMB/FU=; b=Gq5I8KgKVf9ovBrDUXpZFe878g0hgmUFfM3bi8pdpRKjCNiTDGnTqzKYxJlW8I/4pM wEbS4ZoCCnHhAoDlNTqa39MzBFpYX0pvEcklZQj5W0iVnWR59diG7mjSWhNcSv8PLFOa An2P2rQAMR/g38d5OSE+5K97nOoTro5ZD2d80FLko7heOetNST301d5fNEBID1JweiQb hosBq2Ebr6pL0DDrWlYTvCAGAOvLXq/WhRC897sO9xlStnEGR1aT1s81QJzMORqZfuJH PFSF7bFDvhM2kB4QEX8nl4kfjwFUuShhP86IDsro0cLleyWOjygMg1iktm1ZHmhTiNFG wmSg== X-Forwarded-Encrypted: i=1; AFNElJ+zGiXBRYCVyrB9vO57BuvlBj78RLUlcIfKK3CzRAXVwU6MjKHwd41avTd2FimY10hq02665Kw=@vger.kernel.org X-Gm-Message-State: AOJu0YwFVQr9jolih75jh4RIyW676/bELxdNPKYeCQPQp4AjMa+SY5AL qR/z9kAIQgJS7mpicFDS1L3XpDaY4Ut/IHexxb9BJobUmfhj0RJEXuip+NUrgJILsJdjUcSrs0H rmPXa6LJ8d2pDsQFdX20YI7jb0Pfok3JSHMl0faeUyRbn+8Rx2vN5fKlCJr8= Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:4d0a:b0:69d:c62a:f33d with SMTP id 006d021491bc7-69edc6e9ffdmr8403761eaf.33.1781508517632; Mon, 15 Jun 2026 00:28:37 -0700 (PDT) Date: Mon, 15 Jun 2026 00:28:37 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a2fa9a5.8812e0fc.3c3fa4.0019.GAE@google.com> Subject: [syzbot] [net?] possible deadlock in __ethtool_get_link_ksettings From: syzbot To: andrew@lunn.ch, davem@davemloft.net, edumazet@google.com, horms@kernel.org, kuba@kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, pabeni@redhat.com, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 2319688890d9 geneve: Fix off-by-one comparing with GRO_LEG.. git tree: net-next console output: https://syzkaller.appspot.com/x/log.txt?x=169064ae580000 kernel config: https://syzkaller.appspot.com/x/.config?x=a0842261b62cdea8 dashboard link: https://syzkaller.appspot.com/bug?extid=9bb8bd77f3966641f298 compiler: Debian clang version 22.1.6 (++20260514074242+fc4aad7b5db3-1~exp1~20260514074407.73), Debian LLD 22.1.6 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/51d0476acca3/disk-23196888.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/7b1b6c54f1f5/vmlinux-23196888.xz kernel image: https://storage.googleapis.com/syzbot-assets/c69ec4023055/bzImage-23196888.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+9bb8bd77f3966641f298@syzkaller.appspotmail.com netlink: 'syz.1.3070': attribute type 10 has an invalid length. netlink: 40 bytes leftover after parsing attributes in process `syz.1.3070'. ============================================ WARNING: possible recursive locking detected syzkaller #0 Not tainted -------------------------------------------- syz.1.3070/18201 is trying to acquire lock: ffff888079ea6e18 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2837 [inline] ffff888079ea6e18 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline] ffff888079ea6e18 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: __ethtool_get_link_ksettings+0x109/0x250 net/ethtool/ioctl.c:463 but task is already holding lock: ffff888079ea6e18 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2837 [inline] ffff888079ea6e18 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline] ffff888079ea6e18 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: do_setlink+0x3d4/0x4670 net/core/rtnetlink.c:3117 and the lock comparison function returns 0: other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&dev_instance_lock_key#3); lock(&dev_instance_lock_key#3); *** DEADLOCK *** May be due to missing lock nesting notation 2 locks held by syz.1.3070/18201: #0: ffffffff8fdc1540 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8fdc1540 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8fdc1540 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_setlink+0x6a7/0xb20 net/core/rtnetlink.c:3527 #1: ffff888079ea6e18 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2837 [inline] #1: ffff888079ea6e18 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline] #1: ffff888079ea6e18 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: do_setlink+0x3d4/0x4670 net/core/rtnetlink.c:3117 stack backtrace: CPU: 0 UID: 0 PID: 18201 Comm: syz.1.3070 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_deadlock_bug+0x279/0x290 kernel/locking/lockdep.c:3041 check_deadlock kernel/locking/lockdep.c:3093 [inline] validate_chain kernel/locking/lockdep.c:3895 [inline] __lock_acquire+0x24bf/0x2cd0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x19d/0x1590 kernel/locking/mutex.c:820 netdev_lock include/linux/netdevice.h:2837 [inline] netdev_lock_ops include/net/netdev_lock.h:42 [inline] __ethtool_get_link_ksettings+0x109/0x250 net/ethtool/ioctl.c:463 __team_port_change_send+0x245/0x560 drivers/net/team/team_core.c:3095 __team_port_change_check drivers/net/team/team_core.c:3139 [inline] team_port_change_check+0x82/0x1d0 drivers/net/team/team_core.c:3160 team_device_event+0x487/0x570 drivers/net/team/team_core.c:3181 notifier_call_chain+0x1a5/0x3d0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2288 [inline] call_netdevice_notifiers net/core/dev.c:2302 [inline] __dev_notify_flags+0x1aa/0x310 net/core/dev.c:9791 netif_change_flags+0xde/0x1b0 net/core/dev.c:9820 dev_change_flags+0x128/0x260 net/core/dev_api.c:68 vlan_device_event+0x1b4e/0x1f00 net/8021q/vlan.c:494 notifier_call_chain+0x1a5/0x3d0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2288 [inline] call_netdevice_notifiers net/core/dev.c:2302 [inline] __dev_notify_flags+0x1aa/0x310 net/core/dev.c:9791 netif_change_flags+0xde/0x1b0 net/core/dev.c:9820 do_setlink+0xdd6/0x4670 net/core/rtnetlink.c:3207 rtnl_setlink+0x77d/0xb20 net/core/rtnetlink.c:3537 rtnetlink_rcv_msg+0x802/0xc00 net/core/rtnetlink.c:7068 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x7bb/0x940 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] ____sys_sendmsg+0x9b9/0xa20 net/socket.c:2699 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2753 __sys_sendmsg net/socket.c:2785 [inline] __do_sys_sendmsg net/socket.c:2790 [inline] __se_sys_sendmsg net/socket.c:2788 [inline] __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2788 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f50af59ce59 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f50b0467028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f50af815fa0 RCX: 00007f50af59ce59 RDX: 0000000000000000 RSI: 0000200000000080 RDI: 0000000000000003 RBP: 00007f50af632d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f50af816038 R14: 00007f50af815fa0 R15: 00007ffee67f33e8 --- 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