==================================================================
BUG: KASAN: use-after-free in mcp2221_raw_event+0x106a/0x1240 drivers/hid/hid-mcp2221.c:948
Read of size 1 at addr ffff888056dbffff by task swapper/0/0

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 10/02/2025
Call Trace:
 <IRQ>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xca/0x240 mm/kasan/report.c:482
 kasan_report+0x118/0x150 mm/kasan/report.c:595
 mcp2221_raw_event+0x106a/0x1240 drivers/hid/hid-mcp2221.c:948
 __hid_input_report drivers/hid/hid-core.c:2139 [inline]
 hid_input_report+0x41d/0x580 drivers/hid/hid-core.c:2166
 hid_irq_in+0x47e/0x6d0 drivers/hid/usbhid/hid-core.c:286
 __usb_hcd_giveback_urb+0x376/0x540 drivers/usb/core/hcd.c:1661
 dummy_timer+0x85f/0x45b0 drivers/usb/gadget/udc/dummy_hcd.c:1995
 __run_hrtimer kernel/time/hrtimer.c:1777 [inline]
 __hrtimer_run_queues+0x52c/0xc60 kernel/time/hrtimer.c:1841
 hrtimer_run_softirq+0x187/0x2b0 kernel/time/hrtimer.c:1858
 handle_softirqs+0x286/0x870 kernel/softirq.c:626
 __do_softirq kernel/softirq.c:660 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:727
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:743
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1052
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:flush_smp_call_function_queue+0x1ed/0x250 kernel/smp.c:626
Code: 00 4d 85 f6 75 16 e8 a2 8f 0b 00 eb 15 e8 9b 8f 0b 00 e8 46 3a a1 09 4d 85 f6 74 ea e8 8c 8f 0b 00 fb 48 c7 04 24 0e 36 e0 45 <4b> c7 04 3c 00 00 00 00 66 43 c7 44 3c 09 00 00 43 c6 44 3c 0b 00
RSP: 0018:ffffffff8dc07ce0 EFLAGS: 00000293
RAX: ffffffff81b57904 RBX: 0000000000000000 RCX: ffffffff8dc93300
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffffff8dc07d90 R08: ffffffff8f7d7577 R09: 1ffffffff1efaeae
R10: dffffc0000000000 R11: fffffbfff1efaeaf R12: 1ffffffff1b80f9c
R13: 0000000000000000 R14: 0000000000000200 R15: dffffc0000000000
 do_idle+0x4a2/0x510 kernel/sched/idle.c:357
 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428
 rest_init+0x2de/0x300 init/main.c:758
 start_kernel+0x3ac/0x410 init/main.c:1208
 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291
 common_startup_64+0x13e/0x147
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x56dbf
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 0000000000000000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 36, tgid 36 (kworker/u8:2), ts 87330943525, free_ts 104582087106
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1851
 prep_new_page mm/page_alloc.c:1859 [inline]
 get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3920
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5214
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2479
 alloc_slab_page mm/slub.c:3063 [inline]
 allocate_slab+0x96/0x350 mm/slub.c:3236
 new_slab mm/slub.c:3290 [inline]
 ___slab_alloc+0xe94/0x18a0 mm/slub.c:4659
 __slab_alloc+0x65/0x100 mm/slub.c:4778
 __slab_alloc_node mm/slub.c:4854 [inline]
 slab_alloc_node mm/slub.c:5276 [inline]
 kmem_cache_alloc_node_noprof+0x4ce/0x710 mm/slub.c:5340
 kmalloc_reserve+0xbd/0x290 net/core/skbuff.c:582
 __alloc_skb+0x142/0x2d0 net/core/skbuff.c:673
 alloc_skb include/linux/skbuff.h:1383 [inline]
 nlmsg_new include/net/netlink.h:1055 [inline]
 inet6_ifmcaddr_notify+0xeb/0x1d0 net/ipv6/mcast.c:909
 __ipv6_dev_mc_inc+0x8a9/0xa50 net/ipv6/mcast.c:973
 addrconf_join_solict net/ipv6/addrconf.c:2246 [inline]
 addrconf_dad_begin net/ipv6/addrconf.c:4099 [inline]
 addrconf_dad_work+0x3d0/0x14b0 net/ipv6/addrconf.c:4227
 process_one_work+0x94a/0x15d0 kernel/workqueue.c:3267
 process_scheduled_works kernel/workqueue.c:3350 [inline]
 worker_thread+0x9b0/0xee0 kernel/workqueue.c:3431
 kthread+0x711/0x8a0 kernel/kthread.c:463
page last free pid 6062 tgid 6062 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1395 [inline]
 __free_frozen_pages+0xbc8/0xd30 mm/page_alloc.c:2948
 __slab_free+0x2e7/0x390 mm/slub.c:5970
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:349
 kasan_slab_alloc include/linux/kasan.h:252 [inline]
 slab_post_alloc_hook mm/slub.c:4978 [inline]
 slab_alloc_node mm/slub.c:5288 [inline]
 __do_kmalloc_node mm/slub.c:5649 [inline]
 __kmalloc_noprof+0x3cf/0x800 mm/slub.c:5662
 kmalloc_noprof include/linux/slab.h:961 [inline]
 kzalloc_noprof include/linux/slab.h:1094 [inline]
 tomoyo_encode2 security/tomoyo/realpath.c:45 [inline]
 tomoyo_encode+0x28b/0x550 security/tomoyo/realpath.c:80
 tomoyo_path_perm+0x2b3/0x4b0 security/tomoyo/file.c:831
 tomoyo_path_symlink+0xa3/0xe0 security/tomoyo/tomoyo.c:212
 security_path_symlink+0x177/0x380 security/security.c:1476
 do_symlinkat+0x107/0x3f0 fs/namei.c:4841
 __do_sys_symlinkat fs/namei.c:4859 [inline]
 __se_sys_symlinkat fs/namei.c:4856 [inline]
 __x64_sys_symlinkat+0x95/0xb0 fs/namei.c:4856
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888056dbfe80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888056dbff00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888056dbff80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                                ^
 ffff888056dc0000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888056dc0080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
----------------
Code disassembly (best guess):
   0:	00 4d 85             	add    %cl,-0x7b(%rbp)
   3:	f6 75 16             	divb   0x16(%rbp)
   6:	e8 a2 8f 0b 00       	call   0xb8fad
   b:	eb 15                	jmp    0x22
   d:	e8 9b 8f 0b 00       	call   0xb8fad
  12:	e8 46 3a a1 09       	call   0x9a13a5d
  17:	4d 85 f6             	test   %r14,%r14
  1a:	74 ea                	je     0x6
  1c:	e8 8c 8f 0b 00       	call   0xb8fad
  21:	fb                   	sti
  22:	48 c7 04 24 0e 36 e0 	movq   $0x45e0360e,(%rsp)
  29:	45
* 2a:	4b c7 04 3c 00 00 00 	movq   $0x0,(%r12,%r15,1) <-- trapping instruction
  31:	00
  32:	66 43 c7 44 3c 09 00 	movw   $0x0,0x9(%r12,%r15,1)
  39:	00
  3a:	43 c6 44 3c 0b 00    	movb   $0x0,0xb(%r12,%r15,1)