From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-io1-f79.google.com (mail-io1-f79.google.com [209.85.166.79]) (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 534F653BE for ; Thu, 17 Jul 2025 08:25:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.79 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752740734; cv=none; b=iQnoGNPXaBcxLsB42ZB6kbvN6FMfapg1VEfD1komXQtezJFtxLMLUOvh997I5cJ2ULKKAmoIWCO7WyPhOmkPiX/QcJ8cYSMqpvW99QUo4bDlIWKLhpXqX8fOit267/Ak05xfsY9bZOFRJUXgdSXr3nRlGTmBF9ZmzyLS/3agNVM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752740734; c=relaxed/simple; bh=JPiIC1w/3TYwWMgDsnjNbolZsuxA6bNDhu+gaYfutxg=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=R+1wQCGxunAJk6+zV1PCxeb0JeszydiAL0MeAI6/ZvlA3abzInXpvygO20cXwoYBulg2PfCcVQC7hgtEuHbd2pS7CaR+uuuhYsmAzjvgTG/LdJSI1nSKOXnKDyxgqTIow0QnLqPJKj6lkutNmqByVC2YbuZtOY/c3bqLj3/H3VA= 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=209.85.166.79 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-io1-f79.google.com with SMTP id ca18e2360f4ac-87632a0275dso65271739f.1 for ; Thu, 17 Jul 2025 01:25:33 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1752740732; x=1753345532; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=eY9aqbGhGyvqVjLTPhhxqcyiCeBk55+9dzBpRxUERic=; b=a18F1ZjXK6sriLheobuu6SmGg2yoW1WLPllEL/sqxGEbufaH3VmExjap7JMBaXsrOy ADv5PKSr34FOBBmb1lu/qhFhl8hScYVeSwqtF1ss4wL+LmueB61YpyArfFwrnqbRQapa ZEFLb0PEdQa9TINDM5Fjh7GMH6MQ7CC9tjT/RnfiIZjGg4vVwPXwNLB2ubEPN4Vqly2n OvS1PHWlhsuydNT7Va8TIHBko+2gP8HDvTlG6uSDE4rwTO1JLesvSpOsYCsElpuTkICY JeqFYBleDnPa+bg70rK4J4PNSaO7ICYXdwv49f3BrOkdzBag3S/z9W0zeEXEau+VHilK CX7Q== X-Forwarded-Encrypted: i=1; AJvYcCV2iWDCI0god/VXXTP9kUjqkvgay8FqYn1JifDjCdiVOekuYgY/23t+ZH6xoGAhgEqlNZDEXidgGZOo+fc=@vger.kernel.org X-Gm-Message-State: AOJu0YyJ9Y5cGYE8vaEu4BPrghBGij0/yLfmLWTKhqxYLj+5ctgHxiR0 FSwecODW45rKCIAl98stgbmZJkG7b5kxLL8aSqzf6SS83qsVuvwLur6dumWYh3uKJz34DlTH0vD 6iIX3ubUc2wg5rVMu+c6hrshcjWsv85vq87M32zbyJjibXLMBOzHW4W1iUaI= X-Google-Smtp-Source: AGHT+IGkBGjgaWMB2XCjyZvBAlVgB2UHG9tSnQejzjNoM6BQvTg1Ju0bY5ox40yz1J2NNECiFGslmKFQMd0+HCuRSHFGFjPB39// Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6602:1348:b0:879:66fe:8d1e with SMTP id ca18e2360f4ac-87c0138865bmr212973739f.8.1752740732360; Thu, 17 Jul 2025 01:25:32 -0700 (PDT) Date: Thu, 17 Jul 2025 01:25:32 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6878b37c.a70a0220.693ce.0041.GAE@google.com> Subject: [syzbot] [kernel?] UBSAN: shift-out-of-bounds in comedi_device_attach 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: 155a3c003e55 Merge tag 'for-6.16/dm-fixes-2' of git://git... git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=11196382580000 kernel config: https://syzkaller.appspot.com/x/.config?x=693e2f5eea496864 dashboard link: https://syzkaller.appspot.com/bug?extid=c7e121cdcbe0b0bce98e compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 userspace arch: i386 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-155a3c00.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/a8464683662c/vmlinux-155a3c00.xz kernel image: https://storage.googleapis.com/syzbot-assets/e74dc5d462a7/bzImage-155a3c00.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+c7e121cdcbe0b0bce98e@syzkaller.appspotmail.com ------------[ cut here ]------------ UBSAN: shift-out-of-bounds in drivers/comedi/drivers/pcl812.c:1152:10 shift exponent 1029 is too large for 32-bit type 'int' CPU: 3 UID: 0 PID: 6168 Comm: syz.0.33 Not tainted 6.16.0-rc6-syzkaller-00002-g155a3c003e55 #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 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:120 ubsan_epilogue lib/ubsan.c:233 [inline] __ubsan_handle_shift_out_of_bounds+0x27f/0x420 lib/ubsan.c:494 comedi_device_attach+0x3b3/0x900 drivers/comedi/drivers.c:996 do_devconfig_ioctl+0x1a7/0x580 drivers/comedi/comedi_fops.c:855 comedi_unlocked_ioctl+0x15bb/0x2e90 drivers/comedi/comedi_fops.c:2136 comedi_compat_ioctl+0x1d0/0x910 drivers/comedi/comedi_fops.c:3201 __do_compat_sys_ioctl fs/ioctl.c:1005 [inline] __se_compat_sys_ioctl fs/ioctl.c:948 [inline] __ia32_compat_sys_ioctl+0x23f/0x370 fs/ioctl.c:948 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x7c/0x3a0 arch/x86/entry/syscall_32.c:306 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf7f15579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f503655c EFLAGS: 00000296 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000040946400 RDX: 00000000800000c0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ---[ end trace ]--- ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 10 06 adc %al,(%rsi) 2: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 6: 10 07 adc %al,(%rdi) 8: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi c: 10 08 adc %cl,(%rax) e: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 1e: 00 51 52 add %dl,0x52(%rcx) 21: 55 push %rbp 22: 89 e5 mov %esp,%ebp 24: 0f 34 sysenter 26: cd 80 int $0x80 * 28: 5d pop %rbp <-- trapping instruction 29: 5a pop %rdx 2a: 59 pop %rcx 2b: c3 ret 2c: 90 nop 2d: 90 nop 2e: 90 nop 2f: 90 nop 30: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi --- 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