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 D5FB21DE4C4 for ; Sun, 19 Oct 2025 09:13:35 +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=1760865217; cv=none; b=dYLkT1DKFWDT+Y8OqCrc5NO0saLYjUs+EhzNo/CC5LzJyyvJrhbtCh4wImMSdlULd7adCQZpeGjTLB1WHLjBxo0FWknU7wXmAglwiyBH8mw/KmswJ+DxAY6f/qRSnzMdMJidElDEiU29TRN/SW8NHA/pWYfo9jgBXBp6W8WuRwU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760865217; c=relaxed/simple; bh=suqT4dDmdOOVurOBiFqZVxsm2O3zT6CRdaYbbgTnbUI=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=rmIVnB+gfdFkAjexgvR7swFfjVGZ/ZxutXe3vr0vo79TAg7rs1VhLHDuFR4NHRPtAh123fLk+OVF5BQuKWa+1sKD149wcXEqDTgiKb0TJSCS/qYT5aFQIh2c7vF0KoJF6+YUo2dKPHX11mbbBwWl6XmUpbsCltMxV7XXEs8+mOk= 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-430db5635d6so2958275ab.3 for ; Sun, 19 Oct 2025 02:13:35 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1760865215; x=1761470015; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=PNybqyDOAzWhDRx2d5SkmVYwuuYPyIcWTu7XfaT2bNk=; b=Y3VslYaTfDTgig44gVrJD1j+92dLNJudS50u/I5lcget3YcIgA0ZthOE2PlnJfYFY4 dcw8UZxQ83MiZemXcHe6HZ+YsZszzWQ+BkhP3FiRM0S3UBNGdu1SVPzpE1Ut5jJJmYsP g7pLcWjYUG7tXnxUze1rrm2BoxlYS89EVNY5kf77UzE3QYG3p8ZUMLLWg2B2uyJqPKs9 wDt2CZR3LZtijEdi+VJk3/3ljZjNfDiMffTHQOrD+5eOYXtSNx4X/YbywY2SJf37o8cE fGRZ6sZH4O1Rlu36QkI6VGgURPuK5rrz/6HfEndboYrHNe+vhy6ep8NHJngz7HcZ7qea 9CZA== X-Forwarded-Encrypted: i=1; AJvYcCV1R8KIicCKr06VugjrOvY2OQi3pOv2io3LsLvcO/siB79KHIkcncQDVgAPIXrgtEV1RX/mlKxIvCue76U=@vger.kernel.org X-Gm-Message-State: AOJu0Yx9bKTQZ9f2BZia37Gh4fvQGMnDDvChff1ANbu+A4acRBCL/YzW +lfghNx4Ky5cEeES1t7HzzrAO2YDG2POAo/lTrZwosxwDYiTqd4RhpGJPdM6z4PuTiYkrpeYRQT LP8qDFG3DTGfg+uR3j+ymWCTUmqDgGH3/qn4Qv7Nr6iHNsPNCbO5UbYJnvyc= X-Google-Smtp-Source: AGHT+IEyblhAPbkA7AgZV8rggV0n7/0jXjcig/5pAVScLXiI5DyyfP9YqVi/9rd1YtVRGlzU7c9R9ql596DXPR4RHWNK5igF4NW1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6e02:17c8:b0:430:ae26:7c28 with SMTP id e9e14a558f8ab-430c524cea2mr158942935ab.1.1760865214996; Sun, 19 Oct 2025 02:13:34 -0700 (PDT) Date: Sun, 19 Oct 2025 02:13:34 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <68f4abbe.050a0220.1186a4.052a.GAE@google.com> Subject: [syzbot] [ocfs2?] divide error in ocfs2_block_group_fill (3) From: syzbot To: jlbec@evilplan.org, joseph.qi@linux.alibaba.com, linux-kernel@vger.kernel.org, mark@fasheh.com, ocfs2-devel@lists.linux.dev, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 9b332cece987 Merge tag 'nfsd-6.18-1' of git://git.kernel.o.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=107b85e2580000 kernel config: https://syzkaller.appspot.com/x/.config?x=c2d7b4143707d3a0 dashboard link: https://syzkaller.appspot.com/bug?extid=fd8af97c7227fe605d95 compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-9b332cec.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/512c0375bad7/vmlinux-9b332cec.xz kernel image: https://storage.googleapis.com/syzbot-assets/458c8c31cc7b/bzImage-9b332cec.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+fd8af97c7227fe605d95@syzkaller.appspotmail.com loop0: detected capacity change from 0 to 32768 ======================================================= WARNING: The mand mount option has been deprecated and and is ignored by this kernel. Remove the mand option from the mount to silence this warning. ======================================================= ocfs2: Mounting device (7,0) on (node local, slot 0) with ordered data mode. Oops: divide error: 0000 [#1] SMP KASAN NOPTI CPU: 0 UID: 0 PID: 5318 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:ocfs2_bg_discontig_add_extent fs/ocfs2/suballoc.c:335 [inline] RIP: 0010:ocfs2_block_group_fill+0x5bd/0xa70 fs/ocfs2/suballoc.c:386 Code: 34 1a 49 81 c6 50 01 00 00 45 0f b7 3f 49 83 c5 02 4c 89 e8 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 eb 03 00 00 44 89 f8 31 d2 <66> 41 f7 75 00 0f b7 d8 4c 89 f0 48 c1 e8 03 42 0f b6 04 20 84 c0 RSP: 0018:ffffc9000fd362a0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000100000 RDX: 0000000000000000 RSI: 00000000000010fe RDI: 00000000000010ff RBP: ffffc9000fd363a8 R08: 00313050554f5247 R09: 00313050554f5247 R10: dffffc0000000000 R11: ffffed100a449001 R12: dffffc0000000000 R13: ffff8880334dc2c2 R14: ffff888052248150 R15: 0000000000000000 FS: 00007f73479876c0(0000) GS:ffff88808d301000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000000 CR3: 000000004280a000 CR4: 0000000000352ef0 Call Trace: ocfs2_block_group_alloc_discontig fs/ocfs2/suballoc.c:634 [inline] ocfs2_block_group_alloc fs/ocfs2/suballoc.c:703 [inline] ocfs2_reserve_suballoc_bits+0x20a6/0x4640 fs/ocfs2/suballoc.c:834 ocfs2_reserve_new_metadata_blocks+0x403/0x940 fs/ocfs2/suballoc.c:984 ocfs2_expand_inline_dir fs/ocfs2/dir.c:2845 [inline] ocfs2_extend_dir+0xc76/0x4870 fs/ocfs2/dir.c:3207 ocfs2_prepare_dir_for_insert+0x2fe8/0x5450 fs/ocfs2/dir.c:4312 ocfs2_mknod+0x819/0x2050 fs/ocfs2/namei.c:297 ocfs2_create+0x1a5/0x440 fs/ocfs2/namei.c:676 vfs_create+0x24e/0x400 fs/namei.c:3493 do_mknodat+0x3c6/0x4d0 fs/namei.c:4372 __do_sys_mknod fs/namei.c:4405 [inline] __se_sys_mknod fs/namei.c:4403 [inline] __x64_sys_mknod+0x8c/0xa0 fs/namei.c:4403 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7346b8eec9 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:00007f7347987038 EFLAGS: 00000246 ORIG_RAX: 0000000000000085 RAX: ffffffffffffffda RBX: 00007f7346de5fa0 RCX: 00007f7346b8eec9 RDX: 0000000000000700 RSI: 0000000000000000 RDI: 0000200000000000 RBP: 00007f7346c11f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7346de6038 R14: 00007f7346de5fa0 R15: 00007fff09db6038 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:ocfs2_bg_discontig_add_extent fs/ocfs2/suballoc.c:335 [inline] RIP: 0010:ocfs2_block_group_fill+0x5bd/0xa70 fs/ocfs2/suballoc.c:386 Code: 34 1a 49 81 c6 50 01 00 00 45 0f b7 3f 49 83 c5 02 4c 89 e8 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 eb 03 00 00 44 89 f8 31 d2 <66> 41 f7 75 00 0f b7 d8 4c 89 f0 48 c1 e8 03 42 0f b6 04 20 84 c0 RSP: 0018:ffffc9000fd362a0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000100000 RDX: 0000000000000000 RSI: 00000000000010fe RDI: 00000000000010ff RBP: ffffc9000fd363a8 R08: 00313050554f5247 R09: 00313050554f5247 R10: dffffc0000000000 R11: ffffed100a449001 R12: dffffc0000000000 R13: ffff8880334dc2c2 R14: ffff888052248150 R15: 0000000000000000 FS: 00007f73479876c0(0000) GS:ffff88808d301000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000000 CR3: 000000004280a000 CR4: 0000000000352ef0 ---------------- Code disassembly (best guess): 0: 34 1a xor $0x1a,%al 2: 49 81 c6 50 01 00 00 add $0x150,%r14 9: 45 0f b7 3f movzwl (%r15),%r15d d: 49 83 c5 02 add $0x2,%r13 11: 4c 89 e8 mov %r13,%rax 14: 48 c1 e8 03 shr $0x3,%rax 18: 42 0f b6 04 20 movzbl (%rax,%r12,1),%eax 1d: 84 c0 test %al,%al 1f: 0f 85 eb 03 00 00 jne 0x410 25: 44 89 f8 mov %r15d,%eax 28: 31 d2 xor %edx,%edx * 2a: 66 41 f7 75 00 divw 0x0(%r13) <-- trapping instruction 2f: 0f b7 d8 movzwl %ax,%ebx 32: 4c 89 f0 mov %r14,%rax 35: 48 c1 e8 03 shr $0x3,%rax 39: 42 0f b6 04 20 movzbl (%rax,%r12,1),%eax 3e: 84 c0 test %al,%al --- 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