[v6.1] UBSAN: shift-out-of-bounds in pcl726_attach

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 3594f306da12 Linux 6.1.147
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=13bf69bc580000
kernel config: https://syzkaller.appspot.com/x/.config?x=30b8ca4950f83e04
dashboard link: https://syzkaller.appspot.com/bug?extid=f2674644db6e7a819be9
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/5b0395e2ec6c/disk-3594f306.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/c3ec331b7d5b/vmlinux-3594f306.xz
kernel image: https://storage.googleapis.com/syzbot-assets/bff42068e062/bzImage-3594f306.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+f26746...@syzkaller.appspotmail.com

================================================================================
UBSAN: shift-out-of-bounds in drivers/comedi/drivers/pcl726.c:331:46
shift exponent 268435461 is too large for 32-bit type 'int'
CPU: 1 PID: 5510 Comm: syz.3.215 Not tainted 6.1.147-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
<TASK>
dump_stack_lvl+0x168/0x22e 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:331
comedi_device_attach+0x515/0x650 drivers/comedi/drivers.c:998
do_devconfig_ioctl drivers/comedi/comedi_fops.c:851 [inline]
comedi_unlocked_ioctl+0x5ec/0xf20 drivers/comedi/comedi_fops.c:2151
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f64fbf8e9a9
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:00007f64fcdd7038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f64fc1b5fa0 RCX: 00007f64fbf8e9a9
RDX: 00002000000000c0 RSI: 0000000040946400 RDI: 0000000000000003
RBP: 00007f64fc010d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f64fc1b5fa0 R15: 00007ffdd4820918
</TASK>
================================================================================


---
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If the report is already addressed, let syzbot know by replying with:
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If you want to undo deduplication, reply with:
#syz undup

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 3594f306da12 Linux 6.1.147
git tree: linux-6.1.y

console output: https://syzkaller.appspot.com/x/log.txt?x=1310e9bc580000

kernel config: https://syzkaller.appspot.com/x/.config?x=30b8ca4950f83e04
dashboard link: https://syzkaller.appspot.com/bug?extid=f2674644db6e7a819be9
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15e72cf0580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14a24f82580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/5b0395e2ec6c/disk-3594f306.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/c3ec331b7d5b/vmlinux-3594f306.xz
kernel image: https://storage.googleapis.com/syzbot-assets/bff42068e062/bzImage-3594f306.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+f26746...@syzkaller.appspotmail.com

================================================================================
UBSAN: shift-out-of-bounds in drivers/comedi/drivers/pcl726.c:331:46
shift exponent 268435461 is too large for 32-bit type 'int'

CPU: 1 PID: 4427 Comm: syz.0.16 Not tainted 6.1.147-syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
<TASK>
dump_stack_lvl+0x168/0x22e 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:331
comedi_device_attach+0x515/0x650 drivers/comedi/drivers.c:998
do_devconfig_ioctl drivers/comedi/comedi_fops.c:851 [inline]
comedi_unlocked_ioctl+0x5ec/0xf20 drivers/comedi/comedi_fops.c:2151
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2

RIP: 0033:0x7fe653d8e9a9

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:00007fff6cbe5bd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fe653fb5fa0 RCX: 00007fe653d8e9a9

RDX: 00002000000000c0 RSI: 0000000040946400 RDI: 0000000000000003

RBP: 00007fe653e10d69 R08: 0000000000000000 R09: 0000000000000000

R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000

R13: 00007fe653fb5fa0 R14: 00007fe653fb5fa0 R15: 0000000000000003
</TASK>
================================================================================


---
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.

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: dbcb8d8e4163 Linux 6.6.100
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1678e9bc580000
kernel config: https://syzkaller.appspot.com/x/.config?x=293251cfa8d8100
dashboard link: https://syzkaller.appspot.com/bug?extid=454978c387d406752b7c

compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/d0b56817a2c3/disk-dbcb8d8e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/f0d646b2f7fa/vmlinux-dbcb8d8e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/1e0b752a5011/bzImage-dbcb8d8e.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:

Reported-by: syzbot+454978...@syzkaller.appspotmail.com

================================================================================
UBSAN: shift-out-of-bounds in drivers/comedi/drivers/pcl726.c:331:46
shift exponent 268435461 is too large for 32-bit type 'int'

CPU: 1 PID: 6090 Comm: syz.0.62 Not tainted 6.6.100-syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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
pcl726_attach+0xab9/0xd40 drivers/comedi/drivers/pcl726.c:331
comedi_device_attach+0x519/0x660 drivers/comedi/drivers.c:998
do_devconfig_ioctl drivers/comedi/comedi_fops.c:855 [inline]
comedi_unlocked_ioctl+0x68d/0xf90 drivers/comedi/comedi_fops.c:2156
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: 0033:0x7fcb8538e9a9

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:00007fcb861d3038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fcb855b5fa0 RCX: 00007fcb8538e9a9

RDX: 00002000000000c0 RSI: 0000000040946400 RDI: 0000000000000003

RBP: 00007fcb85410d69 R08: 0000000000000000 R09: 0000000000000000

R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000

R13: 0000000000000000 R14: 00007fcb855b5fa0 R15: 00007ffc966df0d8

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: dbcb8d8e4163 Linux 6.6.100
git tree: linux-6.6.y

console output: https://syzkaller.appspot.com/x/log.txt?x=12263ca2580000

kernel config: https://syzkaller.appspot.com/x/.config?x=293251cfa8d8100
dashboard link: https://syzkaller.appspot.com/bug?extid=454978c387d406752b7c
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=159f2cf0580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=127eaca2580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/d0b56817a2c3/disk-dbcb8d8e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/f0d646b2f7fa/vmlinux-dbcb8d8e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/1e0b752a5011/bzImage-dbcb8d8e.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+454978...@syzkaller.appspotmail.com

================================================================================
UBSAN: shift-out-of-bounds in drivers/comedi/drivers/pcl726.c:331:46
shift exponent 268435461 is too large for 32-bit type 'int'

CPU: 0 PID: 5943 Comm: syz.0.16 Not tainted 6.6.100-syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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
pcl726_attach+0xab9/0xd40 drivers/comedi/drivers/pcl726.c:331
comedi_device_attach+0x519/0x660 drivers/comedi/drivers.c:998
do_devconfig_ioctl drivers/comedi/comedi_fops.c:855 [inline]
comedi_unlocked_ioctl+0x68d/0xf90 drivers/comedi/comedi_fops.c:2156
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: 0033:0x7fef3f38e9a9

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:00007ffc3e50cb58 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fef3f5b5fa0 RCX: 00007fef3f38e9a9

RDX: 00002000000000c0 RSI: 0000000040946400 RDI: 0000000000000003

RBP: 00007fef3f410d69 R08: 0000000000000000 R09: 0000000000000000

R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000

R13: 00007fef3f5b5fa0 R14: 00007fef3f5b5fa0 R15: 0000000000000003

[syzbot]

syzbot suspects this issue was fixed by commit:

commit 5a33d07c94ba91306093e823112a7aa9727549f6
Author: Edward Adam Davis <ead...@qq.com>
Date: Mon Jul 7 12:39:58 2025 +0000

comedi: pcl726: Prevent invalid irq number

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1015b942580000
start commit: 3594f306da12 Linux 6.1.147
git tree: linux-6.1.y

kernel config: https://syzkaller.appspot.com/x/.config?x=30b8ca4950f83e04
dashboard link: https://syzkaller.appspot.com/bug?extid=f2674644db6e7a819be9

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16324f82580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12b72cf0580000

If the result looks correct, please mark the issue as fixed by replying with:

#syz fix: comedi: pcl726: Prevent invalid irq number

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

[syzbot]

syzbot suspects this issue was fixed by commit:

commit 0eb4ed2aa261dee228f1668dbfa6d87353e8162d

Author: Edward Adam Davis <ead...@qq.com>
Date: Mon Jul 7 12:39:58 2025 +0000

comedi: pcl726: Prevent invalid irq number

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1411585b980000
start commit: dbcb8d8e4163 Linux 6.6.100
git tree: linux-6.6.y

kernel config: https://syzkaller.appspot.com/x/.config?x=293251cfa8d8100
dashboard link: https://syzkaller.appspot.com/bug?extid=454978c387d406752b7c

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=159f2cf0580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=127eaca2580000