From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo1-f79.google.com (mail-oo1-f79.google.com [209.85.161.79]) (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 625D03655C4 for ; Thu, 21 May 2026 15:30:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.161.79 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779377444; cv=none; b=Ig68HLy3O5P2uQ2ZlCAtbxbtlzxQ6sOBc2ITGyNWop6qw8DgihWAnzcmVF4I7U3arOtrX58FfeNHrh4uvLtj3GmRtzsois3qH6hg+vtewJzKlKe32yCLNnU5MB4OSTf10+ooiLOhZi4xhtRcJKeOAECPEAuYCKQxbR69f9y9bb8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779377444; c=relaxed/simple; bh=qQ3WmnpZoBLzGW1KoNVan4yZ9Dtr3lzFHGc6nBvdH8E=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=J914UZr9ltkDZEYh9Nb7m/0K5w1FmmVr4xA8pnAbavgllY8O5fMGe2FjDYvgftftOQweU8SB3y2idXAWGxuCI3Ds+cvct9+7GNBK8oyS7z/Iy+6O3HJlSq8MMecyuNqHCh/hjklatmWvvHMOGbq8u0MZf5sKAjSLlwL6WuNxYkY= 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=209.85.161.79 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-oo1-f79.google.com with SMTP id 006d021491bc7-69d0a1cb4a1so16592847eaf.0 for ; Thu, 21 May 2026 08:30:43 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1779377442; x=1779982242; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=vmA4Z0vipzBH5heEkgVH3bTMW+0VOd18FCozAEpQ62E=; b=V2Syw6lNOCsdAyM1nQ2pSRuvNr4GpgSsPoNcvPqZDmR2IIO5slpbnea7jaTv65c9E6 peFGAfVUcA70yOSpTGcekEfW5Lqcw5h1zNOd/N/+fVW9ZrFG82WpO/pOVvSzEvMliKeT gkK8Sq8Teib0UJlvJjDpcpWuNE1/UNfkur/FkIQgO17WPXw0dSCmFQHC2w9nKZrp7OLo xCA1O+yqjRMa2gWA1MHw4XmW/134Q7g6O+ZNLczqpLQX0sOmZ5bTU5JCbNp/EbWPUGNR //TPkngf3tRkiUEXcXQ/9T42vtw3AdiyvkBusKyVKM6FI5Yk9/wrPkWdjyX00kwAwkx1 Tbrg== X-Forwarded-Encrypted: i=1; AFNElJ/XjUUz5aNbx4AavST2oc3Yi+yGt129IUx219XsOOHdOQr3YXFT8evv+rrK8nEfviLtackQWZYc5Pyq478=@vger.kernel.org X-Gm-Message-State: AOJu0YyaCu9m9N9LSLZUPTOp67hhi4IfXHf8/8mTqOEoKctaTYkt7YJB kroKq9LSnnEp4JYhEY68bhx4Hm6ijxGJkDyuY6QkkZZUtyM9E2UneRgKYUhmkPCoPRxj4DZAjjT mJ1GAWGOnBTd0pmKuEv10bF6e0gKNDv774GfgfgSB1h0dmFyIKWO3DloTUHc= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:811:b0:694:9252:1992 with SMTP id 006d021491bc7-69d6ec9897emr1631560eaf.0.1779377442353; Thu, 21 May 2026 08:30:42 -0700 (PDT) Date: Thu, 21 May 2026 08:30:42 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a0f2522.170a0220.55718.0294.GAE@google.com> Subject: [syzbot] [comedi?] general protection fault in comedi_get_is_subdevice_running 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: e98d21c170b0 Add linux-next specific files for 20260508 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=13321306580000 kernel config: https://syzkaller.appspot.com/x/.config?x=59b98218d9b2edf4 dashboard link: https://syzkaller.appspot.com/bug?extid=f24c3d5d316011bacc70 compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/66f2a00ee290/disk-e98d21c1.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/6b982257ce9e/vmlinux-e98d21c1.xz kernel image: https://storage.googleapis.com/syzbot-assets/a73fbea43e1a/bzImage-e98d21c1.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+f24c3d5d316011bacc70@syzkaller.appspotmail.com Oops: general protection fault, probably for non-canonical address 0xdffffc0000000014: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x00000000000000a0-0x00000000000000a7] CPU: 0 UID: 0 PID: 18526 Comm: irq/7-comedi_pa Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:kasan_byte_accessible+0x12/0x30 mm/kasan/generic.c:210 Code: 79 ff ff ff 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 40 d6 48 c1 ef 03 48 b8 00 00 00 00 00 fc ff df <0f> b6 04 07 3c 08 0f 92 c0 e9 80 cc 08 09 cc 66 66 66 66 66 66 2e RSP: 0018:ffffc9000477f9a0 EFLAGS: 00010206 RAX: dffffc0000000000 RBX: ffffffff8b35f873 RCX: 0000000080000001 RDX: 0000000000000000 RSI: ffffffff8b35f873 RDI: 0000000000000014 RBP: ffffffff888f752a R08: 0000000000000001 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffffff88920660 R12: 0000000000000000 R13: 00000000000000a0 R14: 00000000000000a0 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888125cc7000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff47d8456b8 CR3: 0000000029342000 CR4: 00000000003526f0 Call Trace: __kasan_check_byte+0x12/0x40 mm/kasan/common.c:573 kasan_check_byte include/linux/kasan.h:402 [inline] lock_acquire+0x84/0x350 kernel/locking/lockdep.c:5844 rt_spin_lock+0x83/0x400 kernel/locking/spinlock_rt.c:56 spin_lock include/linux/spinlock_rt.h:45 [inline] comedi_get_is_subdevice_running+0x2a/0x130 drivers/comedi/comedi_fops.c:715 comedi_buf_write_samples+0x29/0x5f0 drivers/comedi/comedi_buf.c:676 parport_interrupt+0x105/0x160 drivers/comedi/drivers/comedi_parport.c:218 irq_thread_fn kernel/irq/manage.c:1143 [inline] irq_forced_thread_fn+0x98/0x120 kernel/irq/manage.c:1165 irq_thread+0x47e/0x6e0 kernel/irq/manage.c:1271 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:kasan_byte_accessible+0x12/0x30 mm/kasan/generic.c:210 Code: 79 ff ff ff 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 40 d6 48 c1 ef 03 48 b8 00 00 00 00 00 fc ff df <0f> b6 04 07 3c 08 0f 92 c0 e9 80 cc 08 09 cc 66 66 66 66 66 66 2e RSP: 0018:ffffc9000477f9a0 EFLAGS: 00010206 RAX: dffffc0000000000 RBX: ffffffff8b35f873 RCX: 0000000080000001 RDX: 0000000000000000 RSI: ffffffff8b35f873 RDI: 0000000000000014 RBP: ffffffff888f752a R08: 0000000000000001 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffffff88920660 R12: 0000000000000000 R13: 00000000000000a0 R14: 00000000000000a0 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888125cc7000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff47d8456b8 CR3: 0000000029342000 CR4: 00000000003526f0 ---------------- Code disassembly (best guess), 4 bytes skipped: 0: 0f 1f 40 00 nopl 0x0(%rax) 4: 90 nop 5: 90 nop 6: 90 nop 7: 90 nop 8: 90 nop 9: 90 nop a: 90 nop b: 90 nop c: 90 nop d: 90 nop e: 90 nop f: 90 nop 10: 90 nop 11: 90 nop 12: 90 nop 13: 90 nop 14: 0f 1f 40 d6 nopl -0x2a(%rax) 18: 48 c1 ef 03 shr $0x3,%rdi 1c: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 23: fc ff df * 26: 0f b6 04 07 movzbl (%rdi,%rax,1),%eax <-- trapping instruction 2a: 3c 08 cmp $0x8,%al 2c: 0f 92 c0 setb %al 2f: e9 80 cc 08 09 jmp 0x908ccb4 34: cc int3 35: 66 data16 36: 66 data16 37: 66 data16 38: 66 data16 39: 66 data16 3a: 66 data16 3b: 2e cs --- 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