==================================================================
BUG: KASAN: use-after-free in mcp2221_raw_event+0x103c/0x10a0 drivers/hid/hid-mcp2221.c:950
Read of size 1 at addr ffff88812a0a7fff by task syz.3.5169/26768

CPU: 0 UID: 0 PID: 26768 Comm: syz.3.5169 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x156/0x4c9 mm/kasan/report.c:482
 kasan_report+0xdf/0x1e0 mm/kasan/report.c:595
 mcp2221_raw_event+0x103c/0x10a0 drivers/hid/hid-mcp2221.c:950
 __hid_input_report.constprop.0+0x314/0x460 drivers/hid/hid-core.c:2139
 hid_irq_in+0x52e/0x6b0 drivers/hid/usbhid/hid-core.c:286
 __usb_hcd_giveback_urb+0x38d/0x610 drivers/usb/core/hcd.c:1657
 usb_hcd_giveback_urb+0x3ca/0x4a0 drivers/usb/core/hcd.c:1741
 dummy_timer+0xd85/0x3670 drivers/usb/gadget/udc/dummy_hcd.c:1995
 __run_hrtimer kernel/time/hrtimer.c:1785 [inline]
 __hrtimer_run_queues+0x50e/0xa70 kernel/time/hrtimer.c:1849
 hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1866
 handle_softirqs+0x1de/0x9d0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xed/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0x8f/0xb0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__sanitizer_cov_trace_pc+0x54/0x70 kernel/kcov.c:222
Code: e9 91 25 ba 05 8b 82 9c 15 00 00 85 c0 74 f1 8b 82 78 15 00 00 83 f8 02 75 e6 48 8b 8a 80 15 00 00 8b 92 7c 15 00 00 48 8b 01 <48> 83 c0 01 48 39 d0 73 cd 48 89 01 48 89 34 c1 e9 57 25 ba 05 0f
RSP: 0018:ffffc90008b3fe60 EFLAGS: 00000246
RAX: 00000000000000de RBX: 1ffff92001167fd0 RCX: ffffc900035b1000
RDX: 0000000000080000 RSI: ffffffff81a15008 RDI: ffff888119615880
RBP: ffffffff878d5e20 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: ffffc90008b3fea0 R15: ffffffff878d5e50
 __se_sys_clock_nanosleep kernel/time/posix-timers.c:1368 [inline]
 __x64_sys_clock_nanosleep+0x258/0x480 kernel/time/posix-timers.c:1368
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0x7b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f184adad04e
Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08
RSP: 002b:00007f1849845f38 EFLAGS: 00000246 ORIG_RAX: 00000000000000e6
RAX: ffffffffffffffda RBX: 00007f18498476c0 RCX: 00007f184adad04e
RDX: 00007f1849845f90 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000140
R13: 0000000000000000 R14: 00007f184b065fa0 R15: 00007ffe4cf4a308
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88812a0a7000 pfn:0x12a0a7
flags: 0x200000000000000(node=0|zone=2)
raw: 0200000000000000 dead000000000100 dead000000000122 0000000000000000
raw: ffff88812a0a7000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 0, migratetype Unmovable, gfp_mask 0xd2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 24938, tgid 24938 (cmp), ts 2560050127579, free_ts 2625961174117
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x153/0x170 mm/page_alloc.c:1889
 prep_new_page mm/page_alloc.c:1897 [inline]
 get_page_from_freelist+0xf10/0x39f0 mm/page_alloc.c:3962
 __alloc_frozen_pages_noprof+0x273/0x2860 mm/page_alloc.c:5250
 alloc_slab_page mm/slub.c:3292 [inline]
 allocate_slab mm/slub.c:3481 [inline]
 new_slab+0xa6/0x6c0 mm/slub.c:3539
 refill_objects+0x26b/0x400 mm/slub.c:7175
 refill_sheaf mm/slub.c:2812 [inline]
 __pcs_replace_empty_main+0x1ab/0x660 mm/slub.c:4615
 alloc_from_pcs mm/slub.c:4717 [inline]
 slab_alloc_node mm/slub.c:4851 [inline]
 kmem_cache_alloc_noprof+0x520/0x6a0 mm/slub.c:4873
 anon_vma_alloc mm/rmap.c:94 [inline]
 __anon_vma_prepare+0x344/0x5e0 mm/rmap.c:201
 __vmf_anon_prepare+0x11f/0x250 mm/memory.c:3734
 vmf_anon_prepare mm/internal.h:502 [inline]
 do_cow_fault mm/memory.c:5819 [inline]
 do_fault mm/memory.c:5935 [inline]
 do_pte_missing mm/memory.c:4477 [inline]
 handle_pte_fault mm/memory.c:6317 [inline]
 __handle_mm_fault+0x82c/0x2d60 mm/memory.c:6455
 handle_mm_fault+0x36d/0xa20 mm/memory.c:6624
 do_user_addr_fault+0x74c/0x11d0 arch/x86/mm/fault.c:1385
 handle_page_fault arch/x86/mm/fault.c:1474 [inline]
 exc_page_fault+0x66/0xc0 arch/x86/mm/fault.c:1527
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
page last free pid 14 tgid 14 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1433 [inline]
 __free_frozen_pages+0x7b1/0xfb0 mm/page_alloc.c:2978
 rcu_do_batch kernel/rcu/tree.c:2617 [inline]
 rcu_core+0x5a2/0x10d0 kernel/rcu/tree.c:2869
 handle_softirqs+0x1de/0x9d0 kernel/softirq.c:622
 run_ksoftirqd kernel/softirq.c:1063 [inline]
 run_ksoftirqd+0x38/0x60 kernel/softirq.c:1055
 smpboot_thread_fn+0x3d3/0xaa0 kernel/smpboot.c:160
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x6c3/0xcb0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Memory state around the buggy address:
 ffff88812a0a7e80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88812a0a7f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88812a0a7f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                                ^
 ffff88812a0a8000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88812a0a8080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
----------------
Code disassembly (best guess):
   0:	e9 91 25 ba 05       	jmp    0x5ba2596
   5:	8b 82 9c 15 00 00    	mov    0x159c(%rdx),%eax
   b:	85 c0                	test   %eax,%eax
   d:	74 f1                	je     0x0
   f:	8b 82 78 15 00 00    	mov    0x1578(%rdx),%eax
  15:	83 f8 02             	cmp    $0x2,%eax
  18:	75 e6                	jne    0x0
  1a:	48 8b 8a 80 15 00 00 	mov    0x1580(%rdx),%rcx
  21:	8b 92 7c 15 00 00    	mov    0x157c(%rdx),%edx
  27:	48 8b 01             	mov    (%rcx),%rax
* 2a:	48 83 c0 01          	add    $0x1,%rax <-- trapping instruction
  2e:	48 39 d0             	cmp    %rdx,%rax
  31:	73 cd                	jae    0x0
  33:	48 89 01             	mov    %rax,(%rcx)
  36:	48 89 34 c1          	mov    %rsi,(%rcx,%rax,8)
  3a:	e9 57 25 ba 05       	jmp    0x5ba2596
  3f:	0f                   	.byte 0xf