From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo2-f8.google.com (mail-oo2-f8.google.com [74.125.231.136]) (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 BCDD0351C06 for ; Wed, 9 Sep 2026 15:19:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.231.136 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788967167; cv=none; b=jiFnKkLH8z9qHL0K5Qyptp28HZzgq6geAMWGH4ZfEOSamYslACbEbHEETVKYo+2sNEX5dXm6J/2+BJbat05STR7klwsKQUB35k6BGGZvlSuS14GECFmAbpTNFtSYGlt2Cy5tpjWp2nlij4asV5PbikN3x/TPjxVRuvKoe7t+aXY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788967167; c=relaxed/simple; bh=fBXbFpbcQbjFQINt1XxYvnOz0zlP+VZPixWHDI+5LpQ=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=mgwJkuH+1MyXV3W4tj/GRpQ5UT7vDG/J9waFPUHlCEifaFB5Qq9z2eWd5UXMF/hu7ikie+Y7aC2WS63A8VlpXeJMRomkTCCRYWfMFTgYol+H9AgRxuOhzjKT/iai20eNHVIYzpyjq2k9o0TZXGlybvFFHJ5Eh8sa9r/JJ6cQdlY= 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=74.125.231.136 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-oo2-f8.google.com with SMTP id 006d021491bc7-6b128c3af4bso502892eaf.0 for ; Wed, 09 Sep 2026 08:19:25 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1788967164; x=1789571964; h=content-type:to:from:subject:message-id:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=poVcBc/nmVPP4K5lL2InQVuUDiv4ng734KLoRF+5fug=; b=UsO6GRQSf3yRC01gvXScCk5fX/SEF7T5JA8Khlx3CQDWdEogAzo2s50saQIbnTtwb4 JGd4C8P8A0JrvqMfaY/lfR2R7r9gPet3+gYfkeFyzFVW3E+QYJyOfyo69wZ0L1tnk4Cr O0okOh6r2YslvcB/+ja15xyB2tGvQdEfbiwIVXRAlCGI8XfX+/YW6aXM8RBrmD0W5HiO t7mZ24l3w8aQTsGMVmsC+r9d+a9BRBrQnJUBkFGPFuEzHm5MEBJTivF3zACtQG0wVWC5 w+2DBCp5Tcr1WZeaZmUYSZJBP6Wd/zSX3pZDEtdMiacz3vTG74hAobWVhZMCqVcXivgx WgOg== X-Forwarded-Encrypted: i=1; AKwUvBwLkg3lGTxIqso6hRnPMmDd4WFfhB0jxx05qrJjxihjk/IPjwTQAWbR1y0dNNT3ZejtMGh5p3KLy4QKrXg=@vger.kernel.org X-Gm-Message-State: AFuF++nL/tGfT24SbV0gX5dmRAZ1/fHX2yLQ0eYPhlvCPUPOVDlAHVLu AXRwohngUlFeHNF0qCG2OT9iY/QEvnu5Yv8srBaYgcTjkay/Q8WNjMv/sJjZKBX8Trqd3rKUQU3 8gSV4ckrWO0/xJ5488t2FmZYE3ZhW7xC0oSsKK1AMYMRXoL+nu8+qd+NS8t8= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:4b97:b0:6bd:5506:aadc with SMTP id 006d021491bc7-6bd5506ae79mr4764719eaf.35.1788967164386; Wed, 09 Sep 2026 08:19:24 -0700 (PDT) Date: Wed, 09 Sep 2026 08:19:24 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6aa178fc.f2639fcc.29487d.0008.GAE@google.com> Subject: [syzbot] [fs?] possible deadlock in ovl_create_object (2) From: syzbot To: dakr@kernel.org, driver-core@lists.linux.dev, gregkh@linuxfoundation.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, rafael@kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 654ae5d73c05 Merge tag 'drm-fixes-2026-09-05' of https://g.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=11860cf9580000 kernel config: https://syzkaller.appspot.com/x/.config?x=8c5c3949d762a91f dashboard link: https://syzkaller.appspot.com/bug?extid=7cab6a19619f1b8efc00 compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/90a1eb1b2bfe/disk-654ae5d7.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/dcbbe9cf09c5/vmlinux-654ae5d7.xz kernel image: https://storage.googleapis.com/syzbot-assets/c80eca6821dd/bzImage-654ae5d7.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+7cab6a19619f1b8efc00@syzkaller.appspotmail.com ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Tainted: G L ------------------------------------------------------ syz.6.857/9678 is trying to acquire lock: ffff88803cd16460 (sb_writers#6){.+.+}-{0:0}, at: ovl_create_object+0x130/0x3b0 fs/overlayfs/dir.c:705 but task is already holding lock: ffff888058c6e948 (&ovl_i_mutex_dir_key[depth]){++++}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline] ffff888058c6e948 (&ovl_i_mutex_dir_key[depth]){++++}-{4:4}, at: lookup_open+0xb13/0x1990 fs/namei.c:4458 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (&ovl_i_mutex_dir_key[depth]){++++}-{4:4}: lock_acquire kernel/locking/lockdep.c:5908 [inline] lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5865 down_read+0x99/0x4c0 kernel/locking/rwsem.c:1574 inode_lock_shared include/linux/fs.h:1039 [inline] lookup_slow+0x42/0x70 fs/namei.c:1935 walk_component fs/namei.c:2282 [inline] lookup_last fs/namei.c:2789 [inline] path_lookupat+0x5e8/0xc40 fs/namei.c:2813 filename_lookup+0x202/0x590 fs/namei.c:2842 kern_path+0x37/0x50 fs/namei.c:3036 lookup_bdev+0xd8/0x2a0 block/bdev.c:1268 bdev_file_open_by_path+0x82/0x330 block/bdev.c:1123 add_device drivers/mtd/devices/block2mtd.c:279 [inline] block2mtd_setup2.isra.0+0x2ee/0xbd0 drivers/mtd/devices/block2mtd.c:459 block2mtd_setup+0xbd/0xd0 drivers/mtd/devices/block2mtd.c:476 param_attr_store+0x199/0x300 kernel/params.c:591 module_attr_store+0x58/0x80 kernel/params.c:906 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:145 kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:345 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x6af/0x1050 fs/read_write.c:687 ksys_write+0x12a/0x250 fs/read_write.c:739 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #3 (param_lock){+.+.}-{4:4}: lock_acquire kernel/locking/lockdep.c:5908 [inline] lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5865 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x1a4/0x1bd0 kernel/locking/mutex.c:821 ieee80211_rate_control_ops_get net/mac80211/rate.c:221 [inline] rate_control_alloc net/mac80211/rate.c:267 [inline] ieee80211_init_rate_ctrl_alg+0x1df/0x3b0 net/mac80211/rate.c:1008 ieee80211_register_hw+0x2c1e/0x4580 net/mac80211/main.c:1561 mac80211_hwsim_new_radio+0x2b08/0x6510 drivers/net/wireless/virtual/mac80211_hwsim_main.c:6138 init_mac80211_hwsim+0x5e2/0x6f0 drivers/net/wireless/virtual/mac80211_hwsim_main.c:7624 do_one_initcall+0x11c/0x6f0 init/main.c:1357 do_initcall_level init/main.c:1419 [inline] do_initcalls init/main.c:1435 [inline] do_basic_setup init/main.c:1455 [inline] kernel_init_freeable+0x6ea/0x7b0 init/main.c:1670 kernel_init+0x21/0x1e0 init/main.c:1560 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 -> #2 (rtnl_mutex){+.+.}-{4:4}: lock_acquire kernel/locking/lockdep.c:5908 [inline] lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5865 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x1a4/0x1bd0 kernel/locking/mutex.c:821 rtnl_lock net/core/rtnetlink.c:80 [inline] rtnetlink_rcv_msg+0x371/0xe90 net/core/rtnetlink.c:7138 netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2556 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x585/0x850 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1900 sock_sendmsg_nosec net/socket.c:800 [inline] __sock_sendmsg net/socket.c:815 [inline] sock_sendmsg+0x394/0x410 net/socket.c:838 splice_to_socket+0xb3c/0x11a0 fs/splice.c:884 do_splice_from fs/splice.c:936 [inline] do_splice+0x109c/0x1fa0 fs/splice.c:1349 __do_splice+0x33b/0x370 fs/splice.c:1431 __do_sys_splice fs/splice.c:1634 [inline] __se_sys_splice fs/splice.c:1616 [inline] __x64_sys_splice+0x187/0x250 fs/splice.c:1616 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&pipe->mutex){+.+.}-{4:4}: lock_acquire kernel/locking/lockdep.c:5908 [inline] lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5865 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x1a4/0x1bd0 kernel/locking/mutex.c:821 pipe_lock fs/pipe.c:91 [inline] pipe_lock+0x69/0x80 fs/pipe.c:88 iter_file_splice_write+0x1fd/0x10b0 fs/splice.c:682 do_splice_from fs/splice.c:936 [inline] do_splice+0x109c/0x1fa0 fs/splice.c:1349 __do_splice+0x33b/0x370 fs/splice.c:1431 __do_sys_splice fs/splice.c:1634 [inline] __se_sys_splice fs/splice.c:1616 [inline] __x64_sys_splice+0x187/0x250 fs/splice.c:1616 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (sb_writers#6){.+.+}-{0:0}: check_prev_add+0xeb/0xe60 kernel/locking/lockdep.c:3181 check_prevs_add kernel/locking/lockdep.c:3300 [inline] validate_chain kernel/locking/lockdep.c:3924 [inline] __lock_acquire+0x1492/0x1ec0 kernel/locking/lockdep.c:5254 lock_acquire kernel/locking/lockdep.c:5908 [inline] lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5865 percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline] percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline] __sb_start_write include/linux/fs/super.h:19 [inline] sb_start_write include/linux/fs/super.h:125 [inline] mnt_want_write+0x6f/0x420 fs/namespace.c:494 ovl_create_object+0x130/0x3b0 fs/overlayfs/dir.c:705 lookup_open+0x1255/0x1990 fs/namei.c:4567 open_last_lookups fs/namei.c:4767 [inline] path_openat+0xa2c/0x2440 fs/namei.c:4997 do_file_open+0x20e/0x430 fs/namei.c:5029 do_sys_openat2+0x10f/0x1e0 fs/open.c:1417 do_sys_open fs/open.c:1423 [inline] __do_sys_openat fs/open.c:1439 [inline] __se_sys_openat fs/open.c:1434 [inline] __x64_sys_openat+0x12d/0x210 fs/open.c:1434 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: sb_writers#6 --> param_lock --> &ovl_i_mutex_dir_key[depth] Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&ovl_i_mutex_dir_key[depth]); lock(param_lock); lock(&ovl_i_mutex_dir_key[depth]); rlock(sb_writers#6); *** DEADLOCK *** locks held by syz.6.857/9678: 2, last CPU#1: #0: ffff88802ba66460 (sb_writers#13){.+.+}-{0:0}, at: lookup_open+0x150/0x1990 fs/namei.c:4451 #1: ffff888058c6e948 (&ovl_i_mutex_dir_key[depth]){++++}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline] #1: ffff888058c6e948 (&ovl_i_mutex_dir_key[depth]){++++}-{4:4}, at: lookup_open+0xb13/0x1990 fs/namei.c:4458 stack backtrace: CPU: 1 UID: 0 PID: 9678 Comm: syz.6.857 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_circular_bug.cold+0x178/0x1be kernel/locking/lockdep.c:2059 check_noncircular+0x146/0x160 kernel/locking/lockdep.c:2191 check_prev_add+0xeb/0xe60 kernel/locking/lockdep.c:3181 check_prevs_add kernel/locking/lockdep.c:3300 [inline] validate_chain kernel/locking/lockdep.c:3924 [inline] __lock_acquire+0x1492/0x1ec0 kernel/locking/lockdep.c:5254 lock_acquire kernel/locking/lockdep.c:5908 [inline] lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5865 percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline] percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline] __sb_start_write include/linux/fs/super.h:19 [inline] sb_start_write include/linux/fs/super.h:125 [inline] mnt_want_write+0x6f/0x420 fs/namespace.c:494 ovl_create_object+0x130/0x3b0 fs/overlayfs/dir.c:705 lookup_open+0x1255/0x1990 fs/namei.c:4567 open_last_lookups fs/namei.c:4767 [inline] path_openat+0xa2c/0x2440 fs/namei.c:4997 do_file_open+0x20e/0x430 fs/namei.c:5029 do_sys_openat2+0x10f/0x1e0 fs/open.c:1417 do_sys_open fs/open.c:1423 [inline] __do_sys_openat fs/open.c:1439 [inline] __se_sys_openat fs/open.c:1434 [inline] __x64_sys_openat+0x12d/0x210 fs/open.c:1434 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2d2539e159 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:00007f2d261d2028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f2d25625fa0 RCX: 00007f2d2539e159 RDX: 0000000000000040 RSI: 0000200000000180 RDI: ffffffffffffff9c RBP: 00007f2d25435024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000023 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2d25626038 R14: 00007f2d25625fa0 R15: 00007ffeef1e4b18 --- 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