Oops: general protection fault, probably for non-canonical address 0xdffffc000000000c: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000060-0x0000000000000067] CPU: 0 UID: 0 PID: 4937 Comm: kworker/0:1H Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 Workqueue: events_highpri f_midi_in_work RIP: 0010:dummy_queue+0x1ba/0xb00 drivers/usb/gadget/udc/dummy_hcd.c:737 Code: 00 49 83 bc 24 c8 05 00 00 00 0f 84 a6 07 00 00 e8 6b 32 39 fa 49 8d 7f 60 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 3c 03 0f 8e 4f 07 00 00 45 8b 7f 60 31 ff RSP: 0018:ffffc9000ec47a28 EFLAGS: 00010006 RAX: dffffc0000000000 RBX: ffff888059c9ad10 RCX: ffffffff87d12d5f RDX: 000000000000000c RSI: ffffffff87d12dd5 RDI: 0000000000000060 RBP: ffff8880288340e0 R08: 0000000000000005 R09: 0000000000000005 R10: 0000000000000003 R11: 0000000000000000 R12: ffff888028834c00 R13: ffff888059c9ad00 R14: ffff8880288340d8 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888123ddc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f862f1eb580 CR3: 00000000326fd000 CR4: 00000000003526f0 Call Trace: usb_ep_queue+0xfa/0x3c0 drivers/usb/gadget/udc/core.c:305 f_midi_do_transmit drivers/usb/gadget/function/f_midi.c:659 [inline] f_midi_transmit drivers/usb/gadget/function/f_midi.c:687 [inline] f_midi_in_work+0x9b0/0x1580 drivers/usb/gadget/function/f_midi.c:707 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322 process_scheduled_works kernel/workqueue.c:3405 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:dummy_queue+0x1ba/0xb00 drivers/usb/gadget/udc/dummy_hcd.c:737 Code: 00 49 83 bc 24 c8 05 00 00 00 0f 84 a6 07 00 00 e8 6b 32 39 fa 49 8d 7f 60 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 3c 03 0f 8e 4f 07 00 00 45 8b 7f 60 31 ff RSP: 0018:ffffc9000ec47a28 EFLAGS: 00010006 RAX: dffffc0000000000 RBX: ffff888059c9ad10 RCX: ffffffff87d12d5f RDX: 000000000000000c RSI: ffffffff87d12dd5 RDI: 0000000000000060 RBP: ffff8880288340e0 R08: 0000000000000005 R09: 0000000000000005 R10: 0000000000000003 R11: 0000000000000000 R12: ffff888028834c00 R13: ffff888059c9ad00 R14: ffff8880288340d8 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888123ddc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f862f1eb580 CR3: 00000000326fd000 CR4: 00000000003526f0 ---------------- Code disassembly (best guess): 0: 00 49 83 add %cl,-0x7d(%rcx) 3: bc 24 c8 05 00 mov $0x5c824,%esp 8: 00 00 add %al,(%rax) a: 0f 84 a6 07 00 00 je 0x7b6 10: e8 6b 32 39 fa call 0xfa393280 15: 49 8d 7f 60 lea 0x60(%r15),%rdi 19: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 20: fc ff df 23: 48 89 fa mov %rdi,%rdx 26: 48 c1 ea 03 shr $0x3,%rdx * 2a: 0f b6 04 02 movzbl (%rdx,%rax,1),%eax <-- trapping instruction 2e: 84 c0 test %al,%al 30: 74 08 je 0x3a 32: 3c 03 cmp $0x3,%al 34: 0f 8e 4f 07 00 00 jle 0x789 3a: 45 8b 7f 60 mov 0x60(%r15),%r15d 3e: 31 ff xor %edi,%edi