From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oa1-f70.google.com (mail-oa1-f70.google.com [209.85.160.70]) (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 31444241696 for ; Mon, 26 Jan 2026 06:33:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.160.70 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769409184; cv=none; b=P63ikB0SU1H93iwEEnn37Jz0D3OtbQZilLdQK/hvGnEM5cEd9esIZmV/+czW7Ts244bGbiw2xrnTOffvd98UnItbV9XN5a12DDYlvmwvYlNThCwUiqnrLce4y3drl/SlRgXYCbPWbCSTJ4+f2QiODVFe5IRuuMPUQxj3TZdnN0o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769409184; c=relaxed/simple; bh=wJEU3e/gT3KrY7S3F5hln0xG0g4fKhC5FiVLjRNN3qM=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=irwohwEckv2ZfFBA3/Uw+xpUkXN8EBNm8vHTV9Vat+bKL2CXEu6kVRsM8ucNG//0LeDSOxjMuce6Gf3zFHxu/WATYbhwsWwMGW2mMTwS0/d7MbkgcZTT/jT5RoYjOL6OBe6MOTR5ZVli5IPjQC6SBwRHKKYx/lXVqGaeIYbaQSs= 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=209.85.160.70 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-oa1-f70.google.com with SMTP id 586e51a60fabf-3ff590953b1so6341405fac.2 for ; Sun, 25 Jan 2026 22:33:02 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1769409182; x=1770013982; h=to:from:subject:message-id:in-reply-to:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=TxZNn8kDit5Fu6cRTEVhwTmuWyPivCYOXmgOsDPoYaE=; b=Lq9w9c127VHHrUNjGpwWiKQhvNo8vUrJpSELgTRm5aPaDnb7SoXiqBYaI/0ufH4MZw TEqJxA7CoBAMVfnqVzBtfjB+bMCSkofm/T2JaUUPBiqoWSXIPCz1W+J3CZSDYZJjMbCk rXpwILC7DgzWYAgVWQdKdqKmOLWka6pOLjVCZOVGhVarQzct68yTvI+Q6hMawCorg572 VbNGHRJpj/XrqokW9NwdBWqxBaMLPvVDYouraruKioZkO075mMaARweZvIzERoP/jqMS /vrlBku75ZbnhK6PnLgji25hZwnuyx2V3prPKGCbw0JQLb/e2b2h/KtpwmYhRAZI9Vj9 sLRw== X-Forwarded-Encrypted: i=1; AJvYcCW9SDMAToWiPO3gqsjkKTKACrUdlvk3WUoL+6SokpDfMFvuJIkIJdpZJJRP3aA3addUbf6NdAmYtgDrUDw=@vger.kernel.org X-Gm-Message-State: AOJu0YyAxkIyg42pZrOl/W2zQEp6S8cKgdwTtYQcOdB81VJQgO1mHDgs NOUjpbm8BpzfvHMJgbnnGkjgY9/ZfMsn86cTL/oehY3uqTiKJ6pI/cTQj0nFoMksbO8Ei113kRK Y4ikziIDr/XNPZj7airpl0LAtLvdt1dxwrgUoUZIxVwxALjD/zINY9ntCjSA= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:458d:b0:65c:fc7b:4c24 with SMTP id 006d021491bc7-662e03df71amr1170833eaf.32.1769409182198; Sun, 25 Jan 2026 22:33:02 -0800 (PST) Date: Sun, 25 Jan 2026 22:33:02 -0800 In-Reply-To: <20260126061729.9345-1-kartikey406@gmail.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <69770a9e.a00a0220.33ccc7.0033.GAE@google.com> Subject: Re: [syzbot] [comedi?] BUG: unable to handle kernel paging request in dt2815_attach From: syzbot To: kartikey406@gmail.com, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot has tested the proposed patch but the reproducer is still triggering an issue: BUG: unable to handle kernel paging request in dt2815_attach dt2815: [PID 5821] ENTER dt2815_attach, it->options[0] = 0x7d dt2815: [PID 5821] after comedi_request_region, dev->iobase = 0x7d dt2815: [PID 5821] About to do FIRST outb, dev = ffff888040506800, dev->iobase = 0x7d BUG: unable to handle page fault for address: 000000007fffff90 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 57fb4067 P4D 57fb4067 PUD 0 Oops: Oops: 0002 [#1] SMP KASAN NOPTI CPU: 0 UID: 0 PID: 5821 Comm: syz.0.18 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:__outb arch/x86/include/asm/shared/io.h:22 [inline] RIP: 0010:dt2815_attach+0x6e0/0x1110 drivers/comedi/drivers/dt2815.c:187 Code: f5 ff 48 bd 00 00 00 00 00 fc ff df 41 80 3c 2c 00 74 12 4c 89 f7 e8 9f 02 f9 00 48 bd 00 00 00 00 00 fc ff df 41 8b 16 ff c2 <31> 66 90 41 0f b6 44 2d 00 84 c0 0f 85 00 08 00 00 8b 33 48 c7 c7 RSP: 0018:ffffc90002a8fa78 EFLAGS: 00010206 RAX: 0000000000000055 RBX: ffff88803405cf98 RCX: c9cdd809989aea00 RDX: 000000000000007e RSI: 0000000080000000 RDI: 0000000000000000 RBP: dffffc0000000000 R08: ffff88801fc247d3 R09: 1ffff11003f848fa R10: dffffc0000000000 R11: ffffed1003f848fb R12: 1ffff110080a0d3a R13: 1ffff1100680b9f3 R14: ffff8880405069d0 R15: ffff888040506800 FS: 00007f8323dfe6c0(0000) GS:ffff88808cf1b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000007fffff90 CR3: 0000000057ff9000 CR4: 0000000000352ef0 Call Trace: comedi_device_attach+0x51f/0x720 drivers/comedi/drivers.c:1069 do_devconfig_ioctl drivers/comedi/comedi_fops.c:928 [inline] comedi_unlocked_ioctl+0x701/0x1240 drivers/comedi/comedi_fops.c:2240 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f832479acb9 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:00007f8323dfe028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f8324a15fa0 RCX: 00007f832479acb9 RDX: 0000200000000080 RSI: 0000000040946400 RDI: 0000000000000003 RBP: 00007f8324808bf7 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f8324a16038 R14: 00007f8324a15fa0 R15: 00007fff45a7cad8 Modules linked in: CR2: 000000007fffff90 ---[ end trace 0000000000000000 ]--- RIP: 0010:__outb arch/x86/include/asm/shared/io.h:22 [inline] RIP: 0010:dt2815_attach+0x6e0/0x1110 drivers/comedi/drivers/dt2815.c:187 Code: f5 ff 48 bd 00 00 00 00 00 fc ff df 41 80 3c 2c 00 74 12 4c 89 f7 e8 9f 02 f9 00 48 bd 00 00 00 00 00 fc ff df 41 8b 16 ff c2 <31> 66 90 41 0f b6 44 2d 00 84 c0 0f 85 00 08 00 00 8b 33 48 c7 c7 RSP: 0018:ffffc90002a8fa78 EFLAGS: 00010206 RAX: 0000000000000055 RBX: ffff88803405cf98 RCX: c9cdd809989aea00 RDX: 000000000000007e RSI: 0000000080000000 RDI: 0000000000000000 RBP: dffffc0000000000 R08: ffff88801fc247d3 R09: 1ffff11003f848fa R10: dffffc0000000000 R11: ffffed1003f848fb R12: 1ffff110080a0d3a R13: 1ffff1100680b9f3 R14: ffff8880405069d0 R15: ffff888040506800 FS: 00007f8323dfe6c0(0000) GS:ffff88808cf1b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000007fffff90 CR3: 0000000057ff9000 CR4: 0000000000352ef0 ---------------- Code disassembly (best guess): 0: f5 cmc 1: ff 48 bd decl -0x43(%rax) 4: 00 00 add %al,(%rax) 6: 00 00 add %al,(%rax) 8: 00 fc add %bh,%ah a: ff lcall (bad) b: df 41 80 filds -0x80(%rcx) e: 3c 2c cmp $0x2c,%al 10: 00 74 12 4c add %dh,0x4c(%rdx,%rdx,1) 14: 89 f7 mov %esi,%edi 16: e8 9f 02 f9 00 call 0xf902ba 1b: 48 bd 00 00 00 00 00 movabs $0xdffffc0000000000,%rbp 22: fc ff df 25: 41 8b 16 mov (%r14),%edx 28: ff c2 inc %edx * 2a: 31 66 90 xor %esp,-0x70(%rsi) <-- trapping instruction 2d: 41 0f b6 44 2d 00 movzbl 0x0(%r13,%rbp,1),%eax 33: 84 c0 test %al,%al 35: 0f 85 00 08 00 00 jne 0x83b 3b: 8b 33 mov (%rbx),%esi 3d: 48 rex.W 3e: c7 .byte 0xc7 3f: c7 .byte 0xc7 Tested on: commit: 63804fed Linux 6.19-rc7 git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=12d6905a580000 kernel config: https://syzkaller.appspot.com/x/.config?x=e2e5d7c9c1e01cf4 dashboard link: https://syzkaller.appspot.com/bug?extid=72f94b474d6e50b71ffc compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8 patch: https://syzkaller.appspot.com/x/patch.diff?x=16a40a44580000