syzbot

 sign-in | mailing list | source | docs
🐞 Open [816]
🐞 Fixed [75]
🐞 Invalid [975]
⬇ Missing Backports [122]
≡ Crashes
Kernel Health Bugs/Month Bug Lifetimes Fuzzing
💬 Send us feedback

UBSAN: shift-out-of-bounds in pcl726_attach

Status: upstream: reported C repro on 2025/07/08 03:45
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+2d6fd444c6491140f297@syzkaller.appspotmail.com
First crash: 51d, last: 19h22m
▶ ▼ Bug presence (1)
Date Name Commit Repro Result
2025/07/08 upstream (ToT) d7b8f8e20813 C [report] UBSAN: shift-out-of-bounds in pcl726_attach
▶ ▼ Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 UBSAN: shift-out-of-bounds in pcl726_attach origin:upstream -1 C 16 18h55m 28d 0/3 upstream: reported C repro on 2025/07/31 13:06
linux-6.6 UBSAN: shift-out-of-bounds in pcl726_attach origin:upstream -1 C 17 18h33m 28d 0/2 upstream: reported C repro on 2025/07/31 14:15
upstream UBSAN: shift-out-of-bounds in pcl726_attach comedi -1 C 318 5d11h 54d 22/29 upstream: reported C repro on 2025/07/05 11:02
▶ ▼ Last patch testing requests (3)
Created Duration User Patch Repo Result
2025/07/24 05:51 13m retest repro linux-5.15.y report log
2025/07/24 05:51 13m retest repro linux-5.15.y report log
2025/07/24 05:51 11m retest repro linux-5.15.y report log

Sample crash report:
================================================================================
UBSAN: shift-out-of-bounds in drivers/comedi/drivers/pcl726.c:332:46
shift exponent -2147450880 is negative
CPU: 1 PID: 4476 Comm: syz.0.16 Not tainted 5.15.186-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 ubsan_epilogue+0xa/0x30 lib/ubsan.c:151
 __ubsan_handle_shift_out_of_bounds+0x37c/0x400 lib/ubsan.c:321
 pcl726_attach+0xab5/0xd40 drivers/comedi/drivers/pcl726.c:332
 comedi_device_attach+0x515/0x650 drivers/comedi/drivers.c:996
 do_devconfig_ioctl drivers/comedi/comedi_fops.c:851 [inline]
 comedi_unlocked_ioctl+0x5ec/0xe90 drivers/comedi/comedi_fops.c:2131
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7efca9a46929
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:00007ffe255aac58 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007efca9c6dfa0 RCX: 00007efca9a46929
RDX: 0000200000000080 RSI: 0000000040946400 RDI: 0000000000000003
RBP: 00007efca9ac8b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007efca9c6dfa0 R14: 00007efca9c6dfa0 R15: 0000000000000003
 </TASK>
================================================================================

Crashes (19):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/08 06:41 linux-5.15.y 3dea0e7f549e 4f67c4ae .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan UBSAN: shift-out-of-bounds in pcl726_attach
2025/07/08 05:41 linux-5.15.y 3dea0e7f549e 4f67c4ae .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan UBSAN: shift-out-of-bounds in pcl726_attach
2025/07/08 04:44 linux-5.15.y 3dea0e7f549e 4f67c4ae .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan UBSAN: shift-out-of-bounds in pcl726_attach
2025/08/28 01:57 linux-5.15.y c79648372d02 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan UBSAN: shift-out-of-bounds in pcl726_attach
2025/08/28 01:57 linux-5.15.y c79648372d02 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan UBSAN: shift-out-of-bounds in pcl726_attach
2025/08/19 10:35 linux-5.15.y c79648372d02 523f460e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan UBSAN: shift-out-of-bounds in pcl726_attach
2025/08/18 06:58 linux-5.15.y c79648372d02 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan UBSAN: shift-out-of-bounds in pcl726_attach
2025/08/18 06:57 linux-5.15.y c79648372d02 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan UBSAN: shift-out-of-bounds in pcl726_attach
2025/08/06 20:13 linux-5.15.y c79648372d02 ffe1dd46 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan UBSAN: shift-out-of-bounds in pcl726_attach
2025/08/06 20:13 linux-5.15.y c79648372d02 ffe1dd46 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan UBSAN: shift-out-of-bounds in pcl726_attach
2025/08/06 09:24 linux-5.15.y c79648372d02 ffe1dd46 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan UBSAN: shift-out-of-bounds in pcl726_attach
2025/08/06 09:23 linux-5.15.y c79648372d02 ffe1dd46 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan UBSAN: shift-out-of-bounds in pcl726_attach
2025/08/06 09:04 linux-5.15.y c79648372d02 ffe1dd46 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan UBSAN: shift-out-of-bounds in pcl726_attach
2025/08/06 09:04 linux-5.15.y c79648372d02 ffe1dd46 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan UBSAN: shift-out-of-bounds in pcl726_attach
2025/08/05 08:36 linux-5.15.y c79648372d02 f5bcc8dc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan UBSAN: shift-out-of-bounds in pcl726_attach
2025/08/05 08:36 linux-5.15.y c79648372d02 f5bcc8dc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan UBSAN: shift-out-of-bounds in pcl726_attach
2025/07/31 13:32 linux-5.15.y c79648372d02 f8f2b4da .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan UBSAN: shift-out-of-bounds in pcl726_attach
2025/07/31 13:31 linux-5.15.y c79648372d02 f8f2b4da .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan UBSAN: shift-out-of-bounds in pcl726_attach
2025/07/08 03:45 linux-5.15.y 3dea0e7f549e 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan UBSAN: shift-out-of-bounds in pcl726_attach
* Struck through repros no longer work on HEAD.