Oops: general protection fault, probably for non-canonical address 0xdffffc0000000011: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000088-0x000000000000008f] CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:snd_usbmidi_do_output+0x22d/0x570 sound/usb/midi.c:310 Code: f8 48 c1 e8 03 42 80 3c 28 00 0f 85 14 03 00 00 89 d8 48 c1 e0 04 4c 8b 64 05 08 49 8d 84 24 88 00 00 00 48 89 c2 48 c1 ea 03 <42> 0f b6 14 2a 84 d2 74 09 80 fa 03 0f 8e ad 02 00 00 48 8b 74 24 RSP: 0018:ffffc90000007b80 EFLAGS: 00010016 RAX: 0000000000000088 RBX: 0000000000000000 RCX: ffffffff894338b8 RDX: 0000000000000011 RSI: ffffffff894338c6 RDI: ffff88805e0fc008 RBP: ffff88805e0fc000 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: dffffc0000000000 R14: ffffed100bc1f80f R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8881246b3000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b32d63fff CR3: 000000007e1d5000 CR4: 0000000000350ef0 Call Trace: snd_usbmidi_error_timer+0x119/0x410 sound/usb/midi.c:362 call_timer_fn+0x19a/0x620 kernel/time/timer.c:1747 expire_timers kernel/time/timer.c:1798 [inline] __run_timers+0x6ef/0x960 kernel/time/timer.c:2372 __run_timer_base kernel/time/timer.c:2384 [inline] __run_timer_base kernel/time/timer.c:2376 [inline] run_timer_base+0x114/0x190 kernel/time/timer.c:2393 run_timer_softirq+0x1a/0x40 kernel/time/timer.c:2403 handle_softirqs+0x219/0x8e0 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: 1d 63 02 e9 9e 5a 7d f5 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d d3 16 17 00 fb f4 77 5a 7d f5 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffffff8e207e08 EFLAGS: 000002c2 RAX: 00000000000ab2b9 RBX: 0000000000000000 RCX: ffffffff8b92fb49 RDX: 0000000000000000 RSI: ffffffff8de5156d RDI: ffffffff8c163a00 RBP: fffffbfff1c52ef8 R08: 0000000000000001 R09: ffffed1017086655 R10: ffff8880b84332ab R11: 0000000000000000 R12: 0000000000000000 R13: ffffffff8e2977c0 R14: ffffffff90abad90 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:757 default_idle_call+0x6d/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x391/0x510 kernel/sched/idle.c:330 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428 rest_init+0x16b/0x2b0 init/main.c:744 start_kernel+0x3ee/0x4d0 init/main.c:1097 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:307 x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:288 common_startup_64+0x13e/0x148 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:snd_usbmidi_do_output+0x22d/0x570 sound/usb/midi.c:310 Code: f8 48 c1 e8 03 42 80 3c 28 00 0f 85 14 03 00 00 89 d8 48 c1 e0 04 4c 8b 64 05 08 49 8d 84 24 88 00 00 00 48 89 c2 48 c1 ea 03 <42> 0f b6 14 2a 84 d2 74 09 80 fa 03 0f 8e ad 02 00 00 48 8b 74 24 RSP: 0018:ffffc90000007b80 EFLAGS: 00010016 RAX: 0000000000000088 RBX: 0000000000000000 RCX: ffffffff894338b8 RDX: 0000000000000011 RSI: ffffffff894338c6 RDI: ffff88805e0fc008 RBP: ffff88805e0fc000 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: dffffc0000000000 R14: ffffed100bc1f80f R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8881246b3000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b32d63fff CR3: 000000007e1d5000 CR4: 0000000000350ef0 ---------------- Code disassembly (best guess): 0: f8 clc 1: 48 c1 e8 03 shr $0x3,%rax 5: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1) a: 0f 85 14 03 00 00 jne 0x324 10: 89 d8 mov %ebx,%eax 12: 48 c1 e0 04 shl $0x4,%rax 16: 4c 8b 64 05 08 mov 0x8(%rbp,%rax,1),%r12 1b: 49 8d 84 24 88 00 00 lea 0x88(%r12),%rax 22: 00 23: 48 89 c2 mov %rax,%rdx 26: 48 c1 ea 03 shr $0x3,%rdx * 2a: 42 0f b6 14 2a movzbl (%rdx,%r13,1),%edx <-- trapping instruction 2f: 84 d2 test %dl,%dl 31: 74 09 je 0x3c 33: 80 fa 03 cmp $0x3,%dl 36: 0f 8e ad 02 00 00 jle 0x2e9 3c: 48 rex.W 3d: 8b .byte 0x8b 3e: 74 24 je 0x64