------------[ cut here ]------------ UBSAN: shift-out-of-bounds in drivers/comedi/drivers/pcl726.c:331:46 shift exponent -2147450880 is negative CPU: 1 UID: 0 PID: 22407 Comm: syz.3.3943 Not tainted 6.17.0-rc1-syzkaller-00111-g24ea63ea3877 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 ubsan_epilogue+0xa/0x40 lib/ubsan.c:233 __ubsan_handle_shift_out_of_bounds+0x386/0x410 lib/ubsan.c:494 pcl726_attach+0xac4/0xd50 drivers/comedi/drivers/pcl726.c:331 comedi_device_attach+0x51f/0x720 drivers/comedi/drivers.c:1006 do_devconfig_ioctl drivers/comedi/comedi_fops.c:872 [inline] comedi_unlocked_ioctl+0x5ff/0x1020 drivers/comedi/comedi_fops.c:2173 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:598 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:584 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fcea2f8ebe9 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:00007fcea3e4b038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fcea31b5fa0 RCX: 00007fcea2f8ebe9 RDX: 0000200000000540 RSI: 0000000040946400 RDI: 0000000000000003 RBP: 00007fcea3011e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fcea31b6038 R14: 00007fcea31b5fa0 R15: 00007ffe6a98b658 ---[ end trace ]---