==================================================================
BUG: KASAN: slab-out-of-bounds in mcp2221_raw_event+0x103c/0x10a0 drivers/hid/hid-mcp2221.c:948
Read of size 1 at addr ffff88813fffbfff by task syz.3.2496/13876

CPU: 0 UID: 0 PID: 13876 Comm: syz.3.2496 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
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/0x1a0 mm/kasan/report.c:595
 mcp2221_raw_event+0x103c/0x10a0 drivers/hid/hid-mcp2221.c:948
 __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:1777 [inline]
 __hrtimer_run_queues+0x516/0x990 kernel/time/hrtimer.c:1841
 hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1858
 handle_softirqs+0x1dd/0x8f0 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:lock_acquire+0x5e/0x330 kernel/locking/lockdep.c:5872
Code: 05 7b 34 3d 0b 83 f8 07 0f 87 a4 02 00 00 48 0f a3 05 06 aa 3e 09 0f 82 6f 02 00 00 8b 35 9e b6 3e 09 85 f6 0f 85 8a 00 00 00 <48> 8b 44 24 30 65 48 2b 05 1d 34 3d 0b 0f 85 b8 02 00 00 48 83 c4
RSP: 0018:ffffc90012ae78f8 EFLAGS: 00000206
RAX: 0000000000000046 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff88dcbbf7 RDI: ffffffff878e97a0
RBP: ffffffff894da3a0 R08: 0000000086db7919 R09: 0000000000000007
R10: 0000000000000200 R11: 0000000000000000 R12: 0000000000000002
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 rcu_read_lock include/linux/rcupdate.h:867 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
 unwind_next_frame+0xd1/0x1ea0 arch/x86/kernel/unwind_orc.c:495
 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x43/0x70 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2540 [inline]
 slab_free mm/slub.c:6670 [inline]
 kfree+0x1ad/0x630 mm/slub.c:6878
 raw_ioctl_ep_write drivers/usb/gadget/legacy/raw_gadget.c:1154 [inline]
 raw_ioctl+0x265/0x2b80 drivers/usb/gadget/legacy/raw_gadget.c:1325
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl fs/ioctl.c:583 [inline]
 __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0x570 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f56da23ab4b
Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00
RSP: 002b:00007f56d8c8df60 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f56da23ab4b
RDX: 00007f56d8c8dfe0 RSI: 0000000040085507 RDI: 0000000000000003
RBP: 0000000000000003 R08: 00007f56da5e0320 R09: 0000000000000000
R10: 0000000000000003 R11: 0000000000000246 R12: 0000200000000040
R13: 0000000000000000 R14: 00007f56da4b5fa0 R15: 00007ffd8b7c3b88
 </TASK>

Allocated by task 13775:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:415
 kmalloc_noprof include/linux/slab.h:957 [inline]
 kzalloc_noprof include/linux/slab.h:1094 [inline]
 alloc_pipe_info+0x10e/0x590 fs/pipe.c:800
 get_pipe_inode fs/pipe.c:896 [inline]
 create_pipe_files+0x8c/0x960 fs/pipe.c:928
 __do_pipe_flags fs/pipe.c:990 [inline]
 do_pipe2+0xbd/0x1e0 fs/pipe.c:1038
 __do_sys_pipe2 fs/pipe.c:1056 [inline]
 __se_sys_pipe2 fs/pipe.c:1054 [inline]
 __x64_sys_pipe2+0x54/0x80 fs/pipe.c:1054
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0x570 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 13775:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x43/0x70 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2540 [inline]
 slab_free mm/slub.c:6670 [inline]
 kfree+0x1ad/0x630 mm/slub.c:6878
 put_pipe_info fs/pipe.c:721 [inline]
 pipe_release+0x27a/0x2c0 fs/pipe.c:744
 __fput+0x3ff/0xb40 fs/file_table.c:468
 fput_close_sync+0x118/0x250 fs/file_table.c:573
 __do_sys_close fs/open.c:1573 [inline]
 __se_sys_close fs/open.c:1558 [inline]
 __x64_sys_close+0x8b/0x120 fs/open.c:1558
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0x570 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88813fffbc00
 which belongs to the cache kmalloc-cg-512 of size 512
The buggy address is located 511 bytes to the right of
 allocated 512-byte region [ffff88813fffbc00, ffff88813fffbe00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x13fff8
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff88811e9c1e01
anon flags: 0x200000000000040(head|node=0|zone=2)
page_type: f5(slab)
raw: 0200000000000040 ffff88810004b140 0000000000000000 0000000000000001
raw: 0000000000000000 0000000000100010 00000000f5000000 ffff88811e9c1e01
head: 0200000000000040 ffff88810004b140 0000000000000000 0000000000000001
head: 0000000000000000 0000000000100010 00000000f5000000 ffff88811e9c1e01
head: 0200000000000002 ffffea0004fffe01 00000000ffffffff 00000000ffffffff
head: ffff88813fff9dc0 0000000000000000 00000000ffffffff 0000000000000004
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 2847, tgid 2847 (klogd), ts 1300170782911, free_ts 1228145694698
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1e1/0x250 mm/page_alloc.c:1884
 prep_new_page mm/page_alloc.c:1892 [inline]
 get_page_from_freelist+0xd57/0x3b20 mm/page_alloc.c:3945
 __alloc_frozen_pages_noprof+0x269/0x2230 mm/page_alloc.c:5240
 alloc_pages_mpol+0xe8/0x410 mm/mempolicy.c:2486
 alloc_slab_page mm/slub.c:3075 [inline]
 allocate_slab mm/slub.c:3248 [inline]
 new_slab+0x2c4/0x440 mm/slub.c:3302
 ___slab_alloc+0xda3/0x1ca0 mm/slub.c:4656
 __slab_alloc.isra.0+0x63/0x110 mm/slub.c:4779
 __slab_alloc_node mm/slub.c:4855 [inline]
 slab_alloc_node mm/slub.c:5251 [inline]
 __do_kmalloc_node mm/slub.c:5656 [inline]
 __kmalloc_node_track_caller_noprof+0x5d4/0x9a0 mm/slub.c:5764
 kmalloc_reserve+0xef/0x2c0 net/core/skbuff.c:608
 __alloc_skb+0x186/0x410 net/core/skbuff.c:690
 alloc_skb include/linux/skbuff.h:1383 [inline]
 alloc_skb_with_frags+0xe0/0x810 net/core/skbuff.c:6714
 sock_alloc_send_pskb+0x801/0x980 net/core/sock.c:2995
 unix_dgram_sendmsg+0x3c7/0x1820 net/unix/af_unix.c:2130
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg net/socket.c:742 [inline]
 __sys_sendto+0x4aa/0x520 net/socket.c:2206
 __do_sys_sendto net/socket.c:2213 [inline]
 __se_sys_sendto net/socket.c:2209 [inline]
 __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2209
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0x570 arch/x86/entry/syscall_64.c:94
page last free pid 13106 tgid 13106 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1433 [inline]
 __free_frozen_pages+0x7d1/0x1010 mm/page_alloc.c:2973
 vfree.part.0+0x12b/0x9d0 mm/vmalloc.c:3466
 vfree+0x55/0x80 mm/vmalloc.c:3443
 hiddev_release+0x3be/0x520 drivers/hid/usbhid/hiddev.c:239
 __fput+0x3ff/0xb40 fs/file_table.c:468
 task_work_run+0x150/0x240 kernel/task_work.c:233
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x829/0x2a30 kernel/exit.c:971
 do_group_exit+0xd5/0x2a0 kernel/exit.c:1112
 __do_sys_exit_group kernel/exit.c:1123 [inline]
 __se_sys_exit_group kernel/exit.c:1121 [inline]
 __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1121
 x64_sys_call+0x14fd/0x1510 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0x570 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88813fffbe80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88813fffbf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88813fffbf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                                                ^
 ffff88813fffc000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88813fffc080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
----------------
Code disassembly (best guess):
   0:	05 7b 34 3d 0b       	add    $0xb3d347b,%eax
   5:	83 f8 07             	cmp    $0x7,%eax
   8:	0f 87 a4 02 00 00    	ja     0x2b2
   e:	48 0f a3 05 06 aa 3e 	bt     %rax,0x93eaa06(%rip)        # 0x93eaa1c
  15:	09
  16:	0f 82 6f 02 00 00    	jb     0x28b
  1c:	8b 35 9e b6 3e 09    	mov    0x93eb69e(%rip),%esi        # 0x93eb6c0
  22:	85 f6                	test   %esi,%esi
  24:	0f 85 8a 00 00 00    	jne    0xb4
* 2a:	48 8b 44 24 30       	mov    0x30(%rsp),%rax <-- trapping instruction
  2f:	65 48 2b 05 1d 34 3d 	sub    %gs:0xb3d341d(%rip),%rax        # 0xb3d3454
  36:	0b
  37:	0f 85 b8 02 00 00    	jne    0x2f5
  3d:	48                   	rex.W
  3e:	83                   	.byte 0x83
  3f:	c4                   	.byte 0xc4