From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ot1-f72.google.com (mail-ot1-f72.google.com [209.85.210.72]) (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 DFEBB3168EE for ; Sat, 17 Oct 2026 21:21:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.72 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792272101; cv=none; b=auMHv8E7WhS6Kt5taBDD2hUEnwpaq8FALEouhO6eywlxjK0CFzlpV3wFR3lbPphmxHAgA6Dc+XbFXLp5qVGG6h70E35+RK9Q3d4bpt+NXE1x5ODijwQR6u4+4Yfxj+2062CoaewzyKmsFnAoRi7MBaBDO7E4WW0DCuWvwY6a8rg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792272101; c=relaxed/simple; bh=/kFfHFRoe408EgWKwNIyFW0hOifIAtJ3KHni0rDxd2A=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=PPP+35HJNseOnaWCEZcdDspkwoZtCA5oDw09F98uEqqcRtkfORqY/OeLkb51uAvE6F2NXuOQNeEBtLO2GPoy7IOvHI0J4jsA7+mF4GECRzGqSv8YSThsPzvaCbmwnDGQ0FIj51hEVDbCxByL/Rr7d7Z8P7X4voTGlX00NzgqOgI= 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=209.85.210.72 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-ot1-f72.google.com with SMTP id 46e09a7af769-8254ce65bfeso1794182a34.0 for ; Sat, 17 Oct 2026 14:21:39 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1792272099; x=1792876899; h=content-type:to:from:subject:message-id:in-reply-to:date :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to:content-type; bh=wiq5SZSeAP0nUEm5Zy0xf68TR8qV63o4MNSaQsjSlFU=; b=e6qApYyflFqaxSWhVj0fyu9q5bhRssCjbgI8Dse1TmZeryxBBlAYQiGTjPRKJoCnqk SfwxhqYM1TzcFmV7LqthwBb2OJ76TRxd9TlVhMfUjr9kqlTFr/wTT6/4///qxzNgLw/B rg6NVLXQ0lMvDj4jI0ECOU8175i/YZeyQ69dvrgSPg9OUThn1BxswkKJKnoX85xFhDOz 0LzyKvB8UJp7zopjA3rcuugptEYhS/jwVofCeMg/5YPWfbFgYfwd5Qx3bOGkzeacMqcl n0+e85NMSOlks8ohRXVP/BU5k2+RxeOeb/dAMJut7pBFU0D4cM08hBHAy3kY9PTNTfRq 3wAg== X-Forwarded-Encrypted: i=1; AKwUvBxf7TZxcIMtR7t0Nn6gVE5GzENcC9L2mVvoHb7/WbyqQcediVyrvxkBdF25k5rUWTDjGwsOieHfA1Kjt+o=@vger.kernel.org X-Gm-Message-State: AFq9FYKwfPnrnROOOvg1x2S4+f8ArPlhlE899BQcM4QWXO8RgtNkeBlD WKrHlkTZ5Sj6ntZM2KdAc4FfJG+lytsuRhyeTeV8SJfI2h3lvFitBTtk3r9l+CzBfKRfQLdPjqi Jq57VRwhx1/AArSZHksnE3+f9GSpCuHdPqVUCsE9go5pjuACo+Xuf/R8vBIE= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6808:2387:b0:4d6:92d4:c804 with SMTP id 5614622812f47-53cd20a090cmr2570349b6e.60.1792272098767; Sat, 17 Oct 2026 14:21:38 -0700 (PDT) Date: Sat, 17 Oct 2026 14:21:38 -0700 In-Reply-To: <6a82cd06.dbb3a75c.20434b.004b.GAE@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6ad3e6e2.a6d1a155.34a93f.004d.GAE@google.com> Subject: Re: [syzbot] [gfs2?] WARNING: kobject bug in __dlm_new_lockspace From: syzbot To: aahringo@redhat.com, gfs2@lists.linux.dev, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, teigland@redhat.com Content-Type: text/plain; charset="UTF-8" syzbot has found a reproducer for the following issue on: HEAD commit: 58161ead29e5 Merge tag 'drm-fixes-2026-10-17' of https://g.. git tree: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git console output: https://syzkaller.appspot.com/x/log.txt?x=121e9495580000 kernel config: https://syzkaller.appspot.com/x/.config?x=c4b098695335c89f dashboard link: https://syzkaller.appspot.com/bug?extid=b2b8d04ec4914f618d23 compiler: Debian clang version 22.1.8 (1~deb13u4), Debian LLD 22.1.8 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=138e8d99580000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+b2b8d04ec4914f618d23@syzkaller.appspotmail.com dlm: Using TCP for communications workqueue: Failed to create a rescuer kthread for wq "dlm_callback": -EINTR dlm: can't start dlm_callback workqueue dlm: ls_6035_1: can't start dlm_callback -12 ------------[ cut here ]------------ kobject: '(null)' (ffff888027a28088): is not initialized, yet kobject_put() is being called. WARNING: lib/kobject.c:736 at kobject_put+0x66/0x550 lib/kobject.c:734, CPU#0: syz-executor183/6040 Modules linked in: CPU: 0 UID: 0 PID: 6040 Comm: syz-executor183 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026 RIP: 0010:kobject_put+0x8e/0x550 lib/kobject.c:734 Code: ae 05 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 08 48 89 df e8 ab 9f 59 f6 48 8b 33 4c 89 f7 48 89 da <67> 48 0f b9 3a eb 05 e8 56 c2 e8 f5 4c 8d 73 38 4c 89 f7 be 04 00 RSP: 0018:ffffc9000307f9f0 EFLAGS: 00010246 RAX: 1ffff11004f45011 RBX: ffff888027a28088 RCX: dffffc0000000000 RDX: ffff888027a28088 RSI: 0000000000000000 RDI: ffffffff918d8000 RBP: 0000000000000000 R08: ffffffff917a747f R09: 1ffffffff22f4e8f R10: dffffc0000000000 R11: fffffbfff22f4e90 R12: 1ffff11004f45018 R13: ffffffff9bad9988 R14: ffffffff918d8000 R15: 00000000fffffff4 FS: 00005555573c3400(0000) GS:ffff888123abf000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6992404000 CR3: 00000000260fb000 CR4: 0000000000350ef0 Call Trace: new_lockspace fs/dlm/lockspace.c:617 [inline] __dlm_new_lockspace+0x1714/0x1cd0 fs/dlm/lockspace.c:638 device_create_lockspace+0xc7/0x350 fs/dlm/user.c:414 device_write+0x872/0xed0 fs/dlm/user.c:606 vfs_write+0x296/0xba0 fs/read_write.c:685 ksys_write+0x150/0x270 fs/read_write.c:739 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f69924444e9 Code: c0 79 93 eb d5 48 8d 7c 1d 00 eb 99 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 d8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd9a54bda8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f69924444e9 RDX: 0000000000000080 RSI: 00007ffd9a54be80 RDI: 0000000000000003 RBP: 00007ffd9a54be80 R08: 00000000ffffffff R09: 0000000084a559bf R10: 00007ffd9a54beb8 R11: 0000000000000246 R12: 0000000000000002 R13: 00007ffd9a54bdd0 R14: 0000000000000001 R15: 00007f6992404000 ---------------- Code disassembly (best guess): 0: ae scas %es:(%rdi),%al 1: 05 48 89 d8 48 add $0x48d88948,%eax 6: c1 e8 03 shr $0x3,%eax 9: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx 10: fc ff df 13: 80 3c 08 00 cmpb $0x0,(%rax,%rcx,1) 17: 74 08 je 0x21 19: 48 89 df mov %rbx,%rdi 1c: e8 ab 9f 59 f6 call 0xf6599fcc 21: 48 8b 33 mov (%rbx),%rsi 24: 4c 89 f7 mov %r14,%rdi 27: 48 89 da mov %rbx,%rdx * 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction 2f: eb 05 jmp 0x36 31: e8 56 c2 e8 f5 call 0xf5e8c28c 36: 4c 8d 73 38 lea 0x38(%rbx),%r14 3a: 4c 89 f7 mov %r14,%rdi 3d: be .byte 0xbe 3e: 04 00 add $0x0,%al --- 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.