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AJvYcCUdNf3exgB3pUm3aRP+oeZn6isz1Qa898TT+C23bXm86Dj52gQ1VCqzRv/x1/ndIgMgXCra/KEa33M7ldE=@vger.kernel.org X-Gm-Message-State: AOJu0YzNVNtzqElsB4FlR7sBtzwfopZPQqHabVpQb1vyjyEDf84DLZkF xozlZNyN2L2c8YJsRHZSw2jGxn4OHyNsIgT4pODV+D8iedshzgiq4P46ePutGnTnRW999iRH/d6 /lBWbw6TeVOA0v/x6L4iFHIIKWXlbp9x9u/ZbN/T1Yke3qyGY5U4OKkUxgYE= X-Google-Smtp-Source: AGHT+IFp2aHAgpgxgKwotpCecd4bB0YiSiL1FRmcmX2yvY8W2cnNVir5HR4z3TaeYeHB2YnbVCd78tGNMluwUmewqsu3gSvCx885 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:b47:b0:3dc:87c7:a5b5 with SMTP id e9e14a558f8ab-3e13ee92ed1mr17189675ab.3.1751713352147; Sat, 05 Jul 2025 04:02:32 -0700 (PDT) Date: Sat, 05 Jul 2025 04:02:32 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <68690648.a00a0220.c7b3.0037.GAE@google.com> Subject: [syzbot] [kernel?] UBSAN: shift-out-of-bounds in pcl726_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: c435a4f487e8 Merge tag 'riscv-for-linus-6.16-rc5' of git:/.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=14ea4f70580000 kernel config: https://syzkaller.appspot.com/x/.config?x=5ba6cef8f153bfeb dashboard link: https://syzkaller.appspot.com/bug?extid=5cd373521edd68bebcb3 compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1116c582580000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12ea4f70580000 Downloadable assets: disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-c435a4f4.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/691cd7284e87/vmlinux-c435a4f4.xz kernel image: https://storage.googleapis.com/syzbot-assets/e61b1a511aab/bzImage-c435a4f4.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+5cd373521edd68bebcb3@syzkaller.appspotmail.com ------------[ cut here ]------------ UBSAN: shift-out-of-bounds in drivers/comedi/drivers/pcl726.c:331:46 shift exponent -2147450880 is negative CPU: 2 UID: 0 PID: 6107 Comm: syz.0.16 Not tainted 6.16.0-rc4-syzkaller-00286-gc435a4f487e8 #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 pcl726_attach.cold+0x19/0x1e drivers/comedi/drivers/pcl726.c:331 comedi_device_attach+0x3b0/0x900 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 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl fs/ioctl.c:893 [inline] __x64_sys_ioctl+0x18b/0x210 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fcefa58e929 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:00007ffd9f2c5a28 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fcefa7b5fa0 RCX: 00007fcefa58e929 RDX: 0000200000002b40 RSI: 0000000040946400 RDI: 0000000000000003 RBP: 00007fcefa610b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fcefa7b5fa0 R14: 00007fcefa7b5fa0 R15: 0000000000000003 ---[ end trace ]--- --- 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 syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing. 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