Oops: divide error: 0000 [#1] SMP KASAN PTI CPU: 0 UID: 0 PID: 18507 Comm: kworker/0:7 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: usb_hub_wq hub_event RIP: 0010:comedi_buf_munge drivers/comedi/comedi_buf.c:347 [inline] RIP: 0010:comedi_buf_write_free+0x3c8/0x7e0 drivers/comedi/comedi_buf.c:391 Code: 41 03 45 00 48 8b 4c 24 78 42 0f b6 0c 21 84 c9 4c 8b bc 24 90 00 00 00 44 8b 74 24 54 0f 85 02 01 00 00 31 d2 48 8b 4c 24 30 31 41 89 55 00 48 8b 44 24 70 42 0f b6 04 20 84 c0 0f 85 09 01 RSP: 0018:ffffc90000007958 EFLAGS: 00010046 RAX: 0000000000000001 RBX: dffffc0000000000 RCX: ffff888034c66680 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff88807b0cc000 RBP: 0000000000000002 R08: 0000000000000000 R09: 00000000000000ff R10: dffffc0000000000 R11: ffffffff88f13960 R12: dffffc0000000000 R13: ffff888034c66638 R14: 0000000000000000 R15: ffff888034c66600 FS: 0000000000000000(0000) GS:ffff8881259f9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c3829c6 CR3: 0000000035496000 CR4: 00000000003526f0 DR0: 000000000000000a DR1: 0000000000000002 DR2: 0000000000000003 DR3: 0000000080000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: comedi_buf_write_samples+0x369/0x5a0 drivers/comedi/comedi_buf.c:602 das16m1_handler+0x213/0x4b0 drivers/comedi/drivers/das16m1.c:413 das16m1_interrupt+0xaf/0x180 drivers/comedi/drivers/das16m1.c:470 __handle_irq_event_percpu+0x295/0xab0 kernel/irq/handle.c:203 handle_irq_event_percpu kernel/irq/handle.c:240 [inline] handle_irq_event+0x8b/0x1e0 kernel/irq/handle.c:257 handle_edge_irq+0x23b/0xa10 kernel/irq/chip.c:855 generic_handle_irq_desc include/linux/irqdesc.h:173 [inline] handle_irq arch/x86/kernel/irq.c:254 [inline] call_irq_handler arch/x86/kernel/irq.c:-1 [inline] __common_interrupt+0x141/0x1f0 arch/x86/kernel/irq.c:325 common_interrupt+0x5e/0xe0 arch/x86/kernel/irq.c:318 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:688 RIP: 0010:variable_ffs arch/x86/include/asm/bitops.h:318 [inline] RIP: 0010:handle_softirqs+0x1b0/0x870 kernel/softirq.c:567 Code: 89 64 24 30 0f b7 db 48 c7 c7 e0 dd a9 8b e8 e7 f3 f8 09 65 66 c7 05 a5 77 3c 11 00 00 e8 f8 78 42 00 fb 49 c7 c7 c0 c0 00 8e ff ff ff ff 0f bc c3 41 89 c5 41 ff c5 0f 84 c2 03 00 00 89 5c RSP: 0018:ffffc90000007e40 EFLAGS: 00000286 RAX: aca989fbb67fb600 RBX: 0000000000000202 RCX: aca989fbb67fb600 RDX: 0000000000000002 RSI: ffffffff8dbbd436 RDI: ffffffff8c037200 RBP: ffffc90000007f50 R08: ffffffff8fc3ee37 R09: 1ffffffff1f87dc6 R10: dffffc0000000000 R11: fffffbfff1f87dc7 R12: 000000000000000a R13: 0000000000000000 R14: dffffc0000000000 R15: ffffffff8e00c0c0 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:console_flush_all+0x7f4/0xb10 arch/x86/include/asm/irqflags.h:-1 Code: ff ff e8 ef 5d 1f 00 90 0f 0b 90 e9 62 fc ff ff e8 e1 5d 1f 00 e8 2c 6a dd 09 48 85 db 74 c0 e8 d2 5d 1f 00 fb 48 8b 5c 24 18 <48> 8b 44 24 20 42 80 3c 20 00 74 08 48 89 df e8 b8 63 83 00 48 8b RSP: 0018:ffffc9000b9f6fe0 EFLAGS: 00000283 RAX: ffffffff81a167ee RBX: ffffffff8ebb8a38 RCX: 0000000000100000 RDX: ffffc90019765000 RSI: 000000000007f3db RDI: 000000000007f3dc RBP: ffffc9000b9f7130 R08: ffffffff8fc3ee37 R09: 1ffffffff1f87dc6 R10: dffffc0000000000 R11: fffffbfff1f87dc7 R12: dffffc0000000000 R13: 0000000000000001 R14: 0000000000000000 R15: ffffffff8ebb89e0 __console_flush_and_unlock kernel/printk/printk.c:3258 [inline] console_unlock+0xbb/0x190 kernel/printk/printk.c:3298 vprintk_emit+0x4c5/0x590 kernel/printk/printk.c:2423 dev_vprintk_emit+0x337/0x3f0 drivers/base/core.c:4914 dev_printk_emit+0xe0/0x130 drivers/base/core.c:4925 _dev_err+0x10a/0x160 drivers/base/core.c:4980 usb_enumerate_device drivers/usb/core/hub.c:2529 [inline] usb_new_device+0x546/0x16f0 drivers/usb/core/hub.c:2664 hub_port_connect drivers/usb/core/hub.c:5566 [inline] hub_port_connect_change drivers/usb/core/hub.c:5706 [inline] port_event drivers/usb/core/hub.c:5870 [inline] hub_event+0x2958/0x4a20 drivers/usb/core/hub.c:5952 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x47c/0x820 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:comedi_buf_munge drivers/comedi/comedi_buf.c:347 [inline] RIP: 0010:comedi_buf_write_free+0x3c8/0x7e0 drivers/comedi/comedi_buf.c:391 Code: 41 03 45 00 48 8b 4c 24 78 42 0f b6 0c 21 84 c9 4c 8b bc 24 90 00 00 00 44 8b 74 24 54 0f 85 02 01 00 00 31 d2 48 8b 4c 24 30 31 41 89 55 00 48 8b 44 24 70 42 0f b6 04 20 84 c0 0f 85 09 01 RSP: 0018:ffffc90000007958 EFLAGS: 00010046 RAX: 0000000000000001 RBX: dffffc0000000000 RCX: ffff888034c66680 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff88807b0cc000 RBP: 0000000000000002 R08: 0000000000000000 R09: 00000000000000ff R10: dffffc0000000000 R11: ffffffff88f13960 R12: dffffc0000000000 R13: ffff888034c66638 R14: 0000000000000000 R15: ffff888034c66600 FS: 0000000000000000(0000) GS:ffff8881259f9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c3829c6 CR3: 0000000035496000 CR4: 00000000003526f0 DR0: 000000000000000a DR1: 0000000000000002 DR2: 0000000000000003 DR3: 0000000080000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 41 03 45 00 add 0x0(%r13),%eax 4: 48 8b 4c 24 78 mov 0x78(%rsp),%rcx 9: 42 0f b6 0c 21 movzbl (%rcx,%r12,1),%ecx e: 84 c9 test %cl,%cl 10: 4c 8b bc 24 90 00 00 mov 0x90(%rsp),%r15 17: 00 18: 44 8b 74 24 54 mov 0x54(%rsp),%r14d 1d: 0f 85 02 01 00 00 jne 0x125 23: 31 d2 xor %edx,%edx 25: 48 8b 4c 24 30 mov 0x30(%rsp),%rcx * 2a: f7 31 divl (%rcx) <-- trapping instruction 2c: 41 89 55 00 mov %edx,0x0(%r13) 30: 48 8b 44 24 70 mov 0x70(%rsp),%rax 35: 42 0f b6 04 20 movzbl (%rax,%r12,1),%eax 3a: 84 c0 test %al,%al 3c: 0f .byte 0xf 3d: 85 09 test %ecx,(%rcx) 3f: 01 .byte 0x1