Oops: divide error: 0000 [#1] SMP KASAN PTI CPU: 0 UID: 0 PID: 14416 Comm: syz.2.1849 Not tainted 6.16.0-next-20250808-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 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:ffffc90000007bd8 EFLAGS: 00010046 RAX: 0000000000000001 RBX: dffffc0000000000 RCX: ffff888031f9f480 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff888024566000 RBP: 0000000000000002 R08: 0000000000000000 R09: 00000000000000ff R10: dffffc0000000000 R11: ffffffff88eec000 R12: dffffc0000000000 R13: ffff888031f9f438 R14: 0000000000000000 R15: ffff888031f9f400 FS: 00007fc8fcb646c0(0000) GS:ffff888125c15000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5130a68f98 CR3: 0000000032f78000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 000000000000000c 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+0x289/0x980 kernel/irq/handle.c:158 handle_irq_event_percpu kernel/irq/handle.c:193 [inline] handle_irq_event+0x8b/0x1e0 kernel/irq/handle.c:210 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+0xb6/0xe0 arch/x86/kernel/irq.c:318 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693 RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline] RIP: 0010:write_comp_data kernel/kcov.c:245 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp1+0x8/0x90 kernel/kcov.c:300 Code: 20 e9 fc 15 be 09 cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 14 25 08 b0 a0 92 65 8b 0d 58 f9 e0 10 81 e1 00 01 ff 00 RSP: 0018:ffffc9001288f6a0 EFLAGS: 00000247 RAX: ffffffff895fe490 RBX: 0000000000000000 RCX: ffffffff895fe474 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000002 RBP: 0000000000000000 R08: ffffffff8fa39a37 R09: 1ffffffff1f47346 R10: dffffc0000000000 R11: fffffbfff1f47347 R12: 0000000000000001 R13: 0000000000000000 R14: ffffc9001288fcf0 R15: ffff888058c5ddc0 variable_test_bit arch/x86/include/asm/bitops.h:227 [inline] arch_test_bit arch/x86/include/asm/bitops.h:239 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:142 [inline] cpumask_test_cpu include/linux/cpumask.h:646 [inline] cpu_online include/linux/cpumask.h:1205 [inline] trace_skb_copy_datagram_iovec include/trace/events/skb.h:76 [inline] skb_copy_datagram_iter+0x80/0x230 net/core/datagram.c:534 skb_copy_datagram_msg include/linux/skbuff.h:4167 [inline] __unix_dgram_recvmsg+0x640/0xd60 net/unix/af_unix.c:2643 sock_recvmsg_nosec+0x186/0x1c0 net/socket.c:1065 ____sys_recvmsg+0x3aa/0x460 net/socket.c:2832 ___sys_recvmsg+0x1b5/0x510 net/socket.c:2876 do_recvmmsg+0x307/0x770 net/socket.c:2971 __sys_recvmmsg net/socket.c:3045 [inline] __do_sys_recvmmsg net/socket.c:3068 [inline] __se_sys_recvmmsg net/socket.c:3061 [inline] __x64_sys_recvmmsg+0x190/0x240 net/socket.c:3061 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: 0033:0x7fc8fbd8ebe9 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:00007fc8fcb64038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007fc8fbfb6090 RCX: 00007fc8fbd8ebe9 RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000004 RBP: 00007fc8fbe11e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc8fbfb6128 R14: 00007fc8fbfb6090 R15: 00007ffd7c303e48 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:ffffc90000007bd8 EFLAGS: 00010046 RAX: 0000000000000001 RBX: dffffc0000000000 RCX: ffff888031f9f480 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff888024566000 RBP: 0000000000000002 R08: 0000000000000000 R09: 00000000000000ff R10: dffffc0000000000 R11: ffffffff88eec000 R12: dffffc0000000000 R13: ffff888031f9f438 R14: 0000000000000000 R15: ffff888031f9f400 FS: 00007fc8fcb646c0(0000) GS:ffff888125c15000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5130a68f98 CR3: 0000000032f78000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 000000000000000c 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