Oops: divide error: 0000 [#1] SMP KASAN PTI CPU: 0 UID: 0 PID: 16029 Comm: syz.3.3200 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 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: ffff88806dfb9080 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8880619f9000 RBP: 0000000000000002 R08: 0000000000000000 R09: 00000000000000ff R10: dffffc0000000000 R11: ffffffff88bb6ff0 R12: dffffc0000000000 R13: ffff88806dfb9038 R14: 0000000000000000 R15: ffff88806dfb9000 FS: 00007f28a77f66c0(0000) GS:ffff888125d18000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b30a23ffc CR3: 0000000061ffa000 CR4: 00000000003526f0 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:312 [inline] RIP: 0010:handle_softirqs+0x1b0/0x870 kernel/softirq.c:610 Code: 89 64 24 30 0f b7 db 48 c7 c7 e0 b3 69 8b e8 77 d8 be 09 65 66 c7 05 45 8c 0b 11 00 00 e8 c8 a6 42 00 fb 49 c7 c7 c0 c0 e0 8d 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: 3a3d1c34223c7600 RBX: 0000000000000008 RCX: 3a3d1c34223c7600 RDX: 0000000000000002 RSI: ffffffff8d80f124 RDI: ffffffff8bc0f3e0 RBP: ffffc90000007f50 R08: ffffffff8f9e6677 R09: 1ffffffff1f3ccce R10: dffffc0000000000 R11: fffffbfff1f3cccf R12: 000000000000000a R13: 0000000000000000 R14: dffffc0000000000 R15: ffffffff8de0c0c0 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 common_interrupt+0xbb/0xe0 arch/x86/kernel/irq.c:318 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:688 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194 Code: 74 05 e8 9b 53 81 f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 d3 da 49 f6 65 8b 05 dc 38 4a 07 85 c0 74 40 48 c7 04 24 0e 36 RSP: 0018:ffffc9000f0e7be0 EFLAGS: 00000206 RAX: 3a3d1c34223c7600 RBX: 0000000000000a02 RCX: 3a3d1c34223c7600 RDX: 0000000000000006 RSI: ffffffff8d80f124 RDI: 0000000000000001 RBP: ffffc9000f0e7c70 R08: ffffffff8f9e6677 R09: 1ffffffff1f3ccce R10: dffffc0000000000 R11: fffffbfff1f3cccf R12: dffffc0000000000 R13: dffffc0000000000 R14: ffffffff99d0ef60 R15: 1ffff92001e1cf7c spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] uart_port_unlock_irqrestore include/linux/serial_core.h:788 [inline] uart_port_unlock_deref+0x111/0x2f0 drivers/tty/serial/serial_core.c:91 uart_write+0xe8/0x130 drivers/tty/serial/serial_core.c:634 tnc_init drivers/net/hamradio/6pack.c:490 [inline] sixpack_open+0x671/0x920 drivers/net/hamradio/6pack.c:580 tty_ldisc_open+0xa1/0x100 drivers/tty/tty_ldisc.c:432 tty_set_ldisc+0x373/0x560 drivers/tty/tty_ldisc.c:563 tty_ioctl+0xc38/0xde0 drivers/tty/tty_io.c:2728 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f28a958eec9 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:00007f28a77f6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f28a97e5fa0 RCX: 00007f28a958eec9 RDX: 0000200000000240 RSI: 0000000000005423 RDI: 0000000000000003 RBP: 00007f28a9611f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f28a97e6038 R14: 00007f28a97e5fa0 R15: 00007ffe550837f8 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: ffff88806dfb9080 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8880619f9000 RBP: 0000000000000002 R08: 0000000000000000 R09: 00000000000000ff R10: dffffc0000000000 R11: ffffffff88bb6ff0 R12: dffffc0000000000 R13: ffff88806dfb9038 R14: 0000000000000000 R15: ffff88806dfb9000 FS: 00007f28a77f66c0(0000) GS:ffff888125d18000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b30a23ffc CR3: 0000000061ffa000 CR4: 00000000003526f0 ---------------- 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