UBSAN: shift-out-of-bounds in pcl812_attach

Status: auto-obsoleted due to no activity on 2025/10/01 18:05
Reported-by: syzbot+e2e9d5c0e8973a1e9950@syzkaller.appspotmail.com
First crash: 385d, last: 375d
Fix bisection: failed (error log, bisect log)
  
▶ ▼ Bug presence (1)
Date Name Commit Repro Result
2025/09/14 upstream (ToT) f83a4f2a4d8c C Didn't crash
▶ ▼ Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream UBSAN: shift-out-of-bounds in pcl812_attach comedi -1 syz, C 288 378d 394d 29/29 fixed on 2025/09/04 16:57
linux-6.1 UBSAN: shift-out-of-bounds in pcl812_attach origin:upstream -1 syz, C done 11 375d 385d 3/3 fixed on 2025/08/28 15:29
linux-5.15 UBSAN: shift-out-of-bounds in pcl812_attach origin:upstream -1 syz, C 90 339d 387d 0/3 auto-obsoleted due to no activity on 2025/11/06 09:23

Sample crash report:
================================================================================
UBSAN: shift-out-of-bounds in drivers/comedi/drivers/pcl812.c:1152:10
shift exponent 8388611 is too large for 32-bit type 'int'
CPU: 0 PID: 23669 Comm: syz.5.4351 Not tainted 6.6.99-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
 ubsan_epilogue+0xa/0x30 lib/ubsan.c:217
 __ubsan_handle_shift_out_of_bounds+0x380/0x400 lib/ubsan.c:387
 pcl812_attach+0x1cd1/0x2440 drivers/comedi/drivers/pcl812.c:1152
 comedi_device_attach+0x519/0x660 drivers/comedi/drivers.c:995
 do_devconfig_ioctl drivers/comedi/comedi_fops.c:855 [inline]
 comedi_unlocked_ioctl+0x68d/0xf00 drivers/comedi/comedi_fops.c:2136
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:871 [inline]
 __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f203838e9a9
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:00007f2039123038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f20385b6080 RCX: 00007f203838e9a9
RDX: 00002000000000c0 RSI: 0000000040946400 RDI: 0000000000000003
RBP: 00007f2038410d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f20385b6080 R15: 00007ffe52f6bdb8
 </TASK>
================================================================================

Crashes (14):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/23 18:04 linux-6.6.y d96eb99e2f0e e1dd4f22 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan UBSAN: shift-out-of-bounds in pcl812_attach
2025/07/23 18:04 linux-6.6.y d96eb99e2f0e e1dd4f22 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan UBSAN: shift-out-of-bounds in pcl812_attach
2025/07/23 16:24 linux-6.6.y d96eb99e2f0e e1dd4f22 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan UBSAN: shift-out-of-bounds in pcl812_attach
2025/07/23 16:24 linux-6.6.y d96eb99e2f0e e1dd4f22 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan UBSAN: shift-out-of-bounds in pcl812_attach
2025/07/22 22:50 linux-6.6.y d96eb99e2f0e 8e9d1dc1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan UBSAN: shift-out-of-bounds in pcl812_attach
2025/07/22 22:50 linux-6.6.y d96eb99e2f0e 8e9d1dc1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan UBSAN: shift-out-of-bounds in pcl812_attach
2025/07/22 22:48 linux-6.6.y d96eb99e2f0e 8e9d1dc1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan UBSAN: shift-out-of-bounds in pcl812_attach
2025/07/17 07:54 linux-6.6.y 9247f4e6573a 44f8051e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan UBSAN: shift-out-of-bounds in pcl812_attach
2025/07/17 07:53 linux-6.6.y 9247f4e6573a 44f8051e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan UBSAN: shift-out-of-bounds in pcl812_attach
2025/07/13 14:40 linux-6.6.y 59a2de10b81a 3cda49cf .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan UBSAN: shift-out-of-bounds in pcl812_attach
2025/07/13 13:54 linux-6.6.y 59a2de10b81a 3cda49cf .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan UBSAN: shift-out-of-bounds in pcl812_attach
2025/07/13 12:57 linux-6.6.y 59a2de10b81a 3cda49cf .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan UBSAN: shift-out-of-bounds in pcl812_attach
2025/07/13 12:10 linux-6.6.y 59a2de10b81a 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan UBSAN: shift-out-of-bounds in pcl812_attach
2025/07/13 12:07 linux-6.6.y 59a2de10b81a 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan UBSAN: shift-out-of-bounds in pcl812_attach
* Struck through repros no longer work on HEAD.