==================================================================
BUG: KASAN: use-after-free in mcp2221_raw_event+0x103c/0x10a0 drivers/hid/hid-mcp2221.c:950
Read of size 1 at addr ffff888133b77fff by task rcu_preempt/15

CPU: 1 UID: 0 PID: 15 Comm: rcu_preempt 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:finish_task_switch.isra.0+0x16a/0x6b0 kernel/sched/core.c:5155
Code: 31 f6 4c 8d 7b 48 e8 95 d6 0a 00 31 f6 48 89 df e8 cb f9 ff ff 4c 89 ff e8 53 fa e3 05 e8 5e d5 35 00 fb 49 8d be 78 15 00 00 <48> b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 04 02 5a
RSP: 0018:ffffc900000ffa50 EFLAGS: 00000206
RAX: 00000000003fc5c5 RBX: ffff8881f57395c0 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff89010a64 RDI: ffff888101ee32f8
RBP: ffffc900000ffa98 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff888105ec5880
R13: 0000000000000000 R14: ffff888101ee1d80 R15: ffff8881f5739608
 context_switch kernel/sched/core.c:5301 [inline]
 __schedule+0xeb9/0x4220 kernel/sched/core.c:6911
 __schedule_loop kernel/sched/core.c:6993 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7008
 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095
 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297
 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
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888133b77f50 pfn:0x133b77
flags: 0x200000000000000(node=0|zone=2)
raw: 0200000000000000 0000000000000000 00000000ffffffff 0000000000000000
raw: ffff888133b77f50 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 18331, tgid 18331 (modprobe), ts 1582172330795, free_ts 1622513084092
 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]
 __prefill_sheaf_pfmemalloc+0x5f/0xb0 mm/slub.c:4936
 kmem_cache_prefill_sheaf+0x1ba/0x4c0 mm/slub.c:5025
 mt_get_sheaf lib/maple_tree.c:189 [inline]
 mas_alloc_nodes+0x2c3/0x390 lib/maple_tree.c:1140
 mas_preallocate+0x39c/0xf10 lib/maple_tree.c:5194
 vma_iter_prealloc mm/vma.h:568 [inline]
 __mmap_new_vma mm/vma.c:2526 [inline]
 __mmap_region+0x11c9/0x26e0 mm/vma.c:2759
 mmap_region+0x180/0x3e0 mm/vma.c:2837
 do_mmap+0xc53/0x12d0 mm/mmap.c:559
 vm_mmap_pgoff+0x201/0x390 mm/util.c:581
 ksys_mmap_pgoff+0xe1/0x650 mm/mmap.c:605
 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline]
 __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline]
 __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0x7b0 arch/x86/entry/syscall_64.c:94
page last free pid 19266 tgid 19266 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
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x47/0xe0 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x4e/0x70 mm/kasan/common.c:350
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4538 [inline]
 slab_alloc_node mm/slub.c:4866 [inline]
 kmem_cache_alloc_noprof+0x2e7/0x6a0 mm/slub.c:4873
 alloc_filename fs/namei.c:142 [inline]
 do_getname+0x35/0x390 fs/namei.c:182
 getname include/linux/fs.h:2512 [inline]
 class_filename_constructor include/linux/fs.h:2539 [inline]
 do_sys_openat2+0xc5/0x1e0 fs/open.c:1365
 do_sys_open fs/open.c:1372 [inline]
 __do_sys_openat fs/open.c:1388 [inline]
 __se_sys_openat fs/open.c:1383 [inline]
 __x64_sys_openat+0x12d/0x210 fs/open.c:1383
 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

Memory state around the buggy address:
 ffff888133b77e80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888133b77f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888133b77f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                                ^
 ffff888133b78000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888133b78080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
----------------
Code disassembly (best guess):
   0:	31 f6                	xor    %esi,%esi
   2:	4c 8d 7b 48          	lea    0x48(%rbx),%r15
   6:	e8 95 d6 0a 00       	call   0xad6a0
   b:	31 f6                	xor    %esi,%esi
   d:	48 89 df             	mov    %rbx,%rdi
  10:	e8 cb f9 ff ff       	call   0xfffff9e0
  15:	4c 89 ff             	mov    %r15,%rdi
  18:	e8 53 fa e3 05       	call   0x5e3fa70
  1d:	e8 5e d5 35 00       	call   0x35d580
  22:	fb                   	sti
  23:	49 8d be 78 15 00 00 	lea    0x1578(%r14),%rdi
* 2a:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax <-- trapping instruction
  31:	fc ff df
  34:	48 89 fa             	mov    %rdi,%rdx
  37:	48 c1 ea 03          	shr    $0x3,%rdx
  3b:	0f b6 04 02          	movzbl (%rdx,%rax,1),%eax
  3f:	5a                   	pop    %rdx