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 6511822D9E6 for ; Wed, 9 Jul 2025 17:38:32 +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=1752082714; cv=none; b=CxxEUwhdoH+cF5yH5CGhC0tzxR+3B9rDfpvk1mYFd80izEktmMzQM65QXWJjaJQqxVZTnuNUOojJq+6sru307odTnA/QUXAnv5xuoD5pchneqfcF1EIThi4InrGscc383RI0Q3347iVXIvlmtSrg+kvHTGCeAFxjlkl1r53HQ4Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752082714; c=relaxed/simple; bh=z9Du3ejSkQ3VkpwRgjKGeib/z5NboU/rZsBL5h6qRn4=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=oySwZpcdXwmYbBHUe/cKeEsU+MO/izgoAgnHrubWV9cze63OW8H/bbOmbmtHsIQfoqOBBtCGouYvX4Nn6Sa5AVsRFCwnLLk58ZfOyNnV5aCH1XBbLsVvbkZis1agHGhdQKH8vyIRnI6h2HmMGPAzMiOoMWzETicFfppfz0corhM= 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-3ddc5137992so1033245ab.2 for ; Wed, 09 Jul 2025 10:38:32 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1752082711; x=1752687511; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=l2kGQvdLAIiltx0MedZ86hxi4iC1DeIZjyAtIJG8XFk=; b=M9LZ7r+kYCGYJZBkigPlRTdYTwE4870bpB80rKwJb019hB7rTiqXBYq+zIM+wjspty XbbBTyyzInMJ3PeqR9CEDoN+0efIqxF4phN9pNgt9xvk6XhX1jPt05JHncmjuao+tGQd aThnkUBGNiNk59dX8RvsjWrYfFcOAvZT3VqGiqjpfKDFlqrfo/rPNpRT+vsCVusWyLMB 8JSYRDtMRAnJBoM9EXY3+SjrKXeNpqLdmlfO4uBDSsComewJoAae0CvFS3HNFwPWEPW4 HfojDnGz0F/w0v/BIiIVuKK4/XZJlDkTcDTLuKjET/VVBYOjyNnOz82QkRyK//qlCgEw Xngw== X-Forwarded-Encrypted: i=1; AJvYcCWS3wUE9d5ufJZV0m0o1wBw/2UicpTj3gTXBxQ82QExfNsnUP0UDjthWN0KDUy+FQ06oBjMTqowowvvDCg=@vger.kernel.org X-Gm-Message-State: AOJu0YwhB/L7/4yEY8e+bw4cFyKn29Qe1Z0EEELAZPcqylhvwNfAzFxP 47KzvtXP9SI67zqe6ePkpEUih/Y9pARvqZh9Ueom6ZSO3bHfqE22qqr/zPtxWZ4jhyfLYaOxbsf 00mn0QnlhViDOH2KmcSWBf7i/hw4A2rF3khiL90ftwIJWcsWgZWckIIL8RHA= X-Google-Smtp-Source: AGHT+IGaBpu568PGYJ6q9DJV3KBNjneYr4VgALWUhlv46bjR5VhFnxnR89D+kuJiXYYn/APUvhcZLw91OXpove294DFMYM/0MqZK Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6e02:12c5:b0:3df:3222:278e with SMTP id e9e14a558f8ab-3e166ffbc65mr33490925ab.1.1752082711252; Wed, 09 Jul 2025 10:38:31 -0700 (PDT) Date: Wed, 09 Jul 2025 10:38:31 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <686ea917.050a0220.385921.0014.GAE@google.com> Subject: [syzbot] [kernel?] divide error in comedi_buf_write_free From: syzbot To: abbotti@mev.co.uk, hsweeten@visionengravers.com, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 58ba80c47402 Add linux-next specific files for 20250708 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=15e9ea8c580000 kernel config: https://syzkaller.appspot.com/x/.config?x=16e0d64c5a66f7ca dashboard link: https://syzkaller.appspot.com/bug?extid=f6c3c066162d2c43a66c compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/27011e78b607/disk-58ba80c4.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/a3b2e0bf7f86/vmlinux-58ba80c4.xz kernel image: https://storage.googleapis.com/syzbot-assets/512dbc2f3800/bzImage-58ba80c4.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+f6c3c066162d2c43a66c@syzkaller.appspotmail.com Oops: divide error: 0000 [#1] SMP KASAN PTI CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.16.0-rc5-next-20250708-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:comedi_buf_munge drivers/comedi/comedi_buf.c:347 [inline] RIP: 0010:comedi_buf_write_free+0x3c8/0x7e0 drivers/comedi/comedi_buf.c:391 Code: 41 03 45 00 48 8b 4c 24 78 42 0f b6 0c 21 84 c9 4c 8b bc 24 90 00 00 00 44 8b 74 24 54 0f 85 02 01 00 00 31 d2 48 8b 4c 24 30 31 41 89 55 00 48 8b 44 24 70 42 0f b6 04 20 84 c0 0f 85 09 01 RSP: 0018:ffffc90000007bd8 EFLAGS: 00010046 RAX: 0000000000000001 RBX: dffffc0000000000 RCX: ffff888030a20880 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff88806b192000 RBP: 0000000000000002 R08: 0000000000000000 R09: 00000000000000ff R10: dffffc0000000000 R11: ffffffff88e91b20 R12: dffffc0000000000 R13: ffff888030a20838 R14: 0000000000000000 R15: ffff888030a20800 FS: 0000000000000000(0000) GS:ffff888125bd7000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007faab2ff5f98 CR3: 0000000033708000 CR4: 00000000003526f0 Call Trace: comedi_buf_write_samples+0x369/0x5a0 drivers/comedi/comedi_buf.c:602 das16m1_handler+0x213/0x4b0 drivers/comedi/drivers/das16m1.c:413 das16m1_interrupt+0xaf/0x180 drivers/comedi/drivers/das16m1.c:470 __handle_irq_event_percpu+0x289/0x980 kernel/irq/handle.c:158 handle_irq_event_percpu kernel/irq/handle.c:193 [inline] handle_irq_event+0x8b/0x1e0 kernel/irq/handle.c:210 handle_edge_irq+0x267/0x9c0 kernel/irq/chip.c:797 generic_handle_irq_desc include/linux/irqdesc.h:173 [inline] handle_irq arch/x86/kernel/irq.c:254 [inline] call_irq_handler arch/x86/kernel/irq.c:266 [inline] __common_interrupt+0x140/0x250 arch/x86/kernel/irq.c:292 common_interrupt+0xb6/0xe0 arch/x86/kernel/irq.c:285 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d c3 ec 0f 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffffff8de07d80 EFLAGS: 000002c6 RAX: 709f8e7c1b77cc00 RBX: ffffffff8196cd28 RCX: 709f8e7c1b77cc00 RDX: 0000000000000001 RSI: ffffffff8d9aefc8 RDI: ffffffff8be33740 RBP: ffffffff8de07ea8 R08: ffff8880b8632f5b R09: 1ffff110170c65eb R10: dffffc0000000000 R11: ffffed10170c65ec R12: ffffffff8fa35430 R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1bd2a50 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:757 default_idle_call+0x74/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x1e8/0x510 kernel/sched/idle.c:330 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428 rest_init+0x2de/0x300 init/main.c:744 start_kernel+0x47d/0x500 init/main.c:1097 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:307 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:288 common_startup_64+0x13e/0x147 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:comedi_buf_munge drivers/comedi/comedi_buf.c:347 [inline] RIP: 0010:comedi_buf_write_free+0x3c8/0x7e0 drivers/comedi/comedi_buf.c:391 Code: 41 03 45 00 48 8b 4c 24 78 42 0f b6 0c 21 84 c9 4c 8b bc 24 90 00 00 00 44 8b 74 24 54 0f 85 02 01 00 00 31 d2 48 8b 4c 24 30 31 41 89 55 00 48 8b 44 24 70 42 0f b6 04 20 84 c0 0f 85 09 01 RSP: 0018:ffffc90000007bd8 EFLAGS: 00010046 RAX: 0000000000000001 RBX: dffffc0000000000 RCX: ffff888030a20880 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff88806b192000 RBP: 0000000000000002 R08: 0000000000000000 R09: 00000000000000ff R10: dffffc0000000000 R11: ffffffff88e91b20 R12: dffffc0000000000 R13: ffff888030a20838 R14: 0000000000000000 R15: ffff888030a20800 FS: 0000000000000000(0000) GS:ffff888125bd7000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007faab2ff5f98 CR3: 0000000033708000 CR4: 00000000003526f0 ---------------- Code disassembly (best guess): 0: 41 03 45 00 add 0x0(%r13),%eax 4: 48 8b 4c 24 78 mov 0x78(%rsp),%rcx 9: 42 0f b6 0c 21 movzbl (%rcx,%r12,1),%ecx e: 84 c9 test %cl,%cl 10: 4c 8b bc 24 90 00 00 mov 0x90(%rsp),%r15 17: 00 18: 44 8b 74 24 54 mov 0x54(%rsp),%r14d 1d: 0f 85 02 01 00 00 jne 0x125 23: 31 d2 xor %edx,%edx 25: 48 8b 4c 24 30 mov 0x30(%rsp),%rcx * 2a: f7 31 divl (%rcx) <-- trapping instruction 2c: 41 89 55 00 mov %edx,0x0(%r13) 30: 48 8b 44 24 70 mov 0x70(%rsp),%rax 35: 42 0f b6 04 20 movzbl (%rax,%r12,1),%eax 3a: 84 c0 test %al,%al 3c: 0f .byte 0xf 3d: 85 09 test %ecx,(%rcx) 3f: 01 .byte 0x1 --- 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