From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oi1-f197.google.com (mail-oi1-f197.google.com [209.85.167.197]) (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 D357F36BCC9 for ; Thu, 26 Feb 2026 06:07:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.197 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772086047; cv=none; b=jBMMH50LEsfHOrNJ8ki5GaxjTGijfoMf8fXCwS0wTT/DqIVkHovzN43AypXYoX2Ujq18vReIeplNBtDNyQyXQ3+HCDQY6pMDqi5+quigmsb8rvlQxqfvKnEpVwXKW9yshQANpeF5C/pTqUzppci433X2qAS0lQOcK65xuktC568= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772086047; c=relaxed/simple; bh=Ggw6zAI22toJswX3uAomFTmkYCm4O9c72cL+2FfP3+0=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=eRTEWdior4Awgepsu+dbUIdR6CakbUAKxoMfcpczxlccxgpGbZQWnx/W6maej+zXkpegz/6LqZBHE3Ih3xpC6Pqp1T6GFmfklBeOabLk7/zrGRQHBH9W2sw0okpOWDg494YJQ3TqTIbP36MlsbMHAp1kpsVtCk4GuMQIDCaY5gI= 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=209.85.167.197 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-oi1-f197.google.com with SMTP id 5614622812f47-45f11f18a89so3184132b6e.2 for ; Wed, 25 Feb 2026 22:07:25 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1772086045; x=1772690845; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=MatsSPIVtuY+WUTnEXIa4ztuXljbJyhy3ptWfpIfBts=; b=Q4FymfZ1FFOa9DA1RZgJL5Dp6hOV07OYVBxdQww4qPFhKsdkLy2I9LF3ZcuegZee68 w9KT42005tH6iNvPsc0IMKDbwnVmFFZaAo1WVJpU0r6WpwC5woyWZb4/4uDWYF+4dr13 GCkvBtFezNJTbuOCxReEI2aXJvRjOBDqqL26gXpu2AvBtoK3vWLCvbXfTqz316v9S2uF VDPVaUF+j8QlfH3tys0S5MlxakCUyOZekTKzc7qbpFkm0ZNCca027IYs4RtjNzkoOYHu duCrp/ZwAMbacG7gUBE1Z8ZE8PwVH30YyyMCAJKxWMD6sdIEgJszEf5fM6di9PWLT47w l1Qw== X-Forwarded-Encrypted: i=1; AJvYcCWv6zKmOe0muKk3ZquisE7sNHSQpFPZhiFsvBsCesq3Oddq0vKegJ6hMAK/gPP5ub1B6wj5c9I=@vger.kernel.org X-Gm-Message-State: AOJu0Yw+SgXslg44+QNn25Ey8LxWBKDaT+7uYhWzKB2EwSn6p1Uba3Wl YkdtfL+6Wv6rkvWcnwS8qtyg5Ki7deWt6bMuVgUcznOy2BclTxVLpZvS1FMP/dnWN1f7inzHvkb lN//TF+/zp4iU05pNSkhEOPV5XwF7FsqTJqC3tmrCKSAnHJ3UHRIMnkk/Zhg= Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:4a87:b0:679:a463:c933 with SMTP id 006d021491bc7-679f3dd6923mr401671eaf.71.1772086044827; Wed, 25 Feb 2026 22:07:24 -0800 (PST) Date: Wed, 25 Feb 2026 22:07:24 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <699fe31c.050a0220.2fcbed.0002.GAE@google.com> Subject: [syzbot] [kernfs?] possible deadlock in __kernfs_remove (3) From: syzbot To: driver-core@lists.linux.dev, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, syzkaller-bugs@googlegroups.com, tj@kernel.org Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: d4f687fbbce4 ovpn: tcp - fix packet extraction from stream git tree: net console output: https://syzkaller.appspot.com/x/log.txt?x=12dba44a580000 kernel config: https://syzkaller.appspot.com/x/.config?x=665cbf0979cda6c5 dashboard link: https://syzkaller.appspot.com/bug?extid=1075f6dc93f398c1857e compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/ee42a61b2ee7/disk-d4f687fb.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/e5470ff18ff8/vmlinux-d4f687fb.xz kernel image: https://storage.googleapis.com/syzbot-assets/d50957aaabf2/bzImage-d4f687fb.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+1075f6dc93f398c1857e@syzkaller.appspotmail.com ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.2.13134/20856 is trying to acquire lock: ffff888064e8e3c8 (kn->active#14){++++}-{0:0}, at: __kernfs_remove+0x3cf/0x660 fs/kernfs/dir.c:1513 but task is already holding lock: ffff888033048788 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6441 [inline] ffff888033048788 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: ieee80211_remove_interfaces+0x132/0x6d0 net/mac80211/iface.c:2415 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&rdev->wiphy.mtx){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:614 [inline] __mutex_lock+0x19f/0x1300 kernel/locking/mutex.c:776 class_wiphy_constructor include/net/cfg80211.h:6441 [inline] ieee80211_change_mac+0xb5/0x1410 net/mac80211/iface.c:324 netif_set_mac_address+0x317/0x4e0 net/core/dev.c:9989 do_setlink+0x9b1/0x4590 net/core/rtnetlink.c:3110 rtnl_changelink net/core/rtnetlink.c:3776 [inline] __rtnl_newlink net/core/rtnetlink.c:3935 [inline] rtnl_newlink+0x15a9/0x1be0 net/core/rtnetlink.c:4072 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:6958 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x80f/0x9b0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0xa68/0xad0 net/socket.c:2592 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2646 __sys_sendmsg net/socket.c:2678 [inline] __do_sys_sendmsg net/socket.c:2683 [inline] __se_sys_sendmsg net/socket.c:2681 [inline] __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2681 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (dev_addr_sem){++++}-{4:4}: down_read+0x47/0x2e0 kernel/locking/rwsem.c:1537 address_show+0x25/0x250 net/core/net-sysfs.c:266 dev_attr_show+0x58/0xc0 drivers/base/core.c:2421 sysfs_kf_seq_show+0x310/0x490 fs/sysfs/file.c:65 seq_read_iter+0x4ef/0xe10 fs/seq_file.c:231 new_sync_read fs/read_write.c:493 [inline] vfs_read+0x582/0xa70 fs/read_write.c:574 ksys_read+0x150/0x270 fs/read_write.c:717 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (kn->active#14){++++}-{0:0}: check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868 kernfs_drain+0x284/0x600 fs/kernfs/dir.c:511 __kernfs_remove+0x3cf/0x660 fs/kernfs/dir.c:1513 kernfs_remove_by_name_ns+0xaf/0x130 fs/kernfs/dir.c:1722 kernfs_remove_by_name include/linux/kernfs.h:633 [inline] remove_files fs/sysfs/group.c:28 [inline] sysfs_remove_group+0xfc/0x2e0 fs/sysfs/group.c:328 sysfs_remove_groups+0x54/0xb0 fs/sysfs/group.c:352 device_remove_groups drivers/base/core.c:2843 [inline] device_remove_attrs+0x229/0x280 drivers/base/core.c:2979 device_del+0x51f/0x8f0 drivers/base/core.c:3877 unregister_netdevice_many_notify+0x1e0e/0x2370 net/core/dev.c:12438 unregister_netdevice_many net/core/dev.c:12466 [inline] unregister_netdevice_queue+0x31f/0x360 net/core/dev.c:12280 unregister_netdevice include/linux/netdevice.h:3408 [inline] _cfg80211_unregister_wdev+0x155/0x570 net/wireless/core.c:1297 ieee80211_remove_interfaces+0x49c/0x6d0 net/mac80211/iface.c:2440 ieee80211_unregister_hw+0x5d/0x2c0 net/mac80211/main.c:1691 mac80211_hwsim_del_radio+0x28a/0x490 drivers/net/wireless/virtual/mac80211_hwsim.c:5916 remove_user_radios drivers/net/wireless/virtual/mac80211_hwsim.c:6727 [inline] mac80211_hwsim_netlink_notify+0xfae/0x1310 drivers/net/wireless/virtual/mac80211_hwsim.c:6741 notifier_call_chain+0x1be/0x400 kernel/notifier.c:85 blocking_notifier_call_chain+0x6a/0x90 kernel/notifier.c:380 netlink_release+0x123b/0x1ad0 net/netlink/af_netlink.c:761 __sock_release net/socket.c:662 [inline] sock_close+0xc3/0x240 net/socket.c:1455 __fput+0x44f/0xa70 fs/file_table.c:469 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: kn->active#14 --> dev_addr_sem --> &rdev->wiphy.mtx Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&rdev->wiphy.mtx); lock(dev_addr_sem); lock(&rdev->wiphy.mtx); lock(kn->active#14); *** DEADLOCK *** 4 locks held by syz.2.13134/20856: #0: ffff88809099c708 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #0: ffff88809099c708 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: __sock_release net/socket.c:661 [inline] #0: ffff88809099c708 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1455 #1: ffffffff8fc374b0 ((netlink_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain+0x54/0x90 kernel/notifier.c:379 #2: ffffffff8fbcb808 (rtnl_mutex){+.+.}-{4:4}, at: ieee80211_unregister_hw+0x55/0x2c0 net/mac80211/main.c:1684 #3: ffff888033048788 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6441 [inline] #3: ffff888033048788 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: ieee80211_remove_interfaces+0x132/0x6d0 net/mac80211/iface.c:2415 stack backtrace: CPU: 0 UID: 0 PID: 20856 Comm: syz.2.13134 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2043 check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868 kernfs_drain+0x284/0x600 fs/kernfs/dir.c:511 __kernfs_remove+0x3cf/0x660 fs/kernfs/dir.c:1513 kernfs_remove_by_name_ns+0xaf/0x130 fs/kernfs/dir.c:1722 kernfs_remove_by_name include/linux/kernfs.h:633 [inline] remove_files fs/sysfs/group.c:28 [inline] sysfs_remove_group+0xfc/0x2e0 fs/sysfs/group.c:328 sysfs_remove_groups+0x54/0xb0 fs/sysfs/group.c:352 device_remove_groups drivers/base/core.c:2843 [inline] device_remove_attrs+0x229/0x280 drivers/base/core.c:2979 device_del+0x51f/0x8f0 drivers/base/core.c:3877 unregister_netdevice_many_notify+0x1e0e/0x2370 net/core/dev.c:12438 unregister_netdevice_many net/core/dev.c:12466 [inline] unregister_netdevice_queue+0x31f/0x360 net/core/dev.c:12280 unregister_netdevice include/linux/netdevice.h:3408 [inline] _cfg80211_unregister_wdev+0x155/0x570 net/wireless/core.c:1297 ieee80211_remove_interfaces+0x49c/0x6d0 net/mac80211/iface.c:2440 ieee80211_unregister_hw+0x5d/0x2c0 net/mac80211/main.c:1691 mac80211_hwsim_del_radio+0x28a/0x490 drivers/net/wireless/virtual/mac80211_hwsim.c:5916 remove_user_radios drivers/net/wireless/virtual/mac80211_hwsim.c:6727 [inline] mac80211_hwsim_netlink_notify+0xfae/0x1310 drivers/net/wireless/virtual/mac80211_hwsim.c:6741 notifier_call_chain+0x1be/0x400 kernel/notifier.c:85 blocking_notifier_call_chain+0x6a/0x90 kernel/notifier.c:380 netlink_release+0x123b/0x1ad0 net/netlink/af_netlink.c:761 __sock_release net/socket.c:662 [inline] sock_close+0xc3/0x240 net/socket.c:1455 __fput+0x44f/0xa70 fs/file_table.c:469 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f182d99c629 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:00007f182e8af028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: 0000000000000018 RBX: 00007f182dc15fa0 RCX: 00007f182d99c629 RDX: 0000000000000300 RSI: 0000200000000040 RDI: 0000000000000004 RBP: 00007f182da32b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f182dc16038 R14: 00007f182dc15fa0 R15: 00007fff4353ce78 --- 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