==================================================================
BUG: KASAN: slab-out-of-bounds in mcp2221_raw_event+0x1062/0x1240 drivers/hid/hid-mcp2221.c:858
Read of size 1 at addr ffff88807c987fff by task syslogd/5123

CPU: 0 PID: 5123 Comm: syslogd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 <IRQ>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0xa8/0x210 mm/kasan/report.c:468
 kasan_report+0x117/0x150 mm/kasan/report.c:581
 mcp2221_raw_event+0x1062/0x1240 drivers/hid/hid-mcp2221.c:858
 hid_input_report+0x400/0x510 drivers/hid/hid-core.c:2103
 hid_irq_in+0x479/0x6d0 drivers/hid/usbhid/hid-core.c:284
 __usb_hcd_giveback_urb+0x35f/0x520 drivers/usb/core/hcd.c:1650
 dummy_timer+0x8de/0x3320 drivers/usb/gadget/udc/dummy_hcd.c:2003
 __run_hrtimer kernel/time/hrtimer.c:1754 [inline]
 __hrtimer_run_queues+0x520/0xc40 kernel/time/hrtimer.c:1818
 hrtimer_run_softirq+0x187/0x2b0 kernel/time/hrtimer.c:1835
 handle_softirqs+0x280/0x820 kernel/softirq.c:578
 __do_softirq kernel/softirq.c:612 [inline]
 invoke_softirq kernel/softirq.c:452 [inline]
 __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661
 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
 sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:finish_task_switch+0x26a/0x8f0 kernel/sched/core.c:5255
Code: 0f 84 33 01 00 00 48 85 db 0f 85 52 01 00 00 0f 1f 44 00 00 4c 8b 75 d0 4c 89 e7 e8 e0 94 34 09 e8 1b 2f 30 00 fb 4c 8b 65 c0 <49> 8d bc 24 f8 15 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0
RSP: 0018:ffffc90003297578 EFLAGS: 00000286
RAX: 0f43e8eb75c48400 RBX: 0000000000000000 RCX: 0f43e8eb75c48400
RDX: dffffc0000000000 RSI: ffffffff8acacbe0 RDI: ffffffff8b1c9c20
RBP: ffffc900032975d0 R08: ffffffff8e8b666f R09: 1ffffffff1d16ccd
R10: dffffc0000000000 R11: fffffbfff1d16cce R12: ffff88807dc6da00
R13: dffffc0000000000 R14: ffff88802a383c00 R15: ffff8880b8e3cb48
 context_switch kernel/sched/core.c:5384 [inline]
 __schedule+0x155b/0x45a0 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 schedule_timeout+0xc1/0x2d0 kernel/time/timer.c:2144
 __skb_wait_for_more_packets+0x3ac/0x590 net/core/datagram.c:120
 __unix_dgram_recvmsg+0x2a4/0xd90 net/unix/af_unix.c:2425
 sock_recvmsg_nosec net/socket.c:1046 [inline]
 sock_recvmsg net/socket.c:1068 [inline]
 sock_read_iter+0x2d9/0x3e0 net/socket.c:1138
 call_read_iter include/linux/fs.h:2012 [inline]
 new_sync_read fs/read_write.c:389 [inline]
 vfs_read+0x46a/0x970 fs/read_write.c:470
 ksys_read+0x150/0x260 fs/read_write.c:613
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f8b38bcd407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffc792c08c0 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007f8b38a7dc80 RCX: 00007f8b38bcd407
RDX: 00000000000000ff RSI: 00005585ae53c950 RDI: 0000000000000000
RBP: 00005585ae53c910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00005585ae53c9df
R13: 0000000000000000 R14: 00005585ae53c950 R15: 000055857ede7d98
 </TASK>

Allocated by task 5435:
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
 ____kasan_kmalloc mm/kasan/common.c:375 [inline]
 __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:384
 kasan_kmalloc include/linux/kasan.h:198 [inline]
 __do_kmalloc_node mm/slab_common.c:1007 [inline]
 __kmalloc_node_track_caller+0xb2/0x230 mm/slab_common.c:1027
 kmalloc_reserve+0x116/0x240 net/core/skbuff.c:584
 __alloc_skb+0x138/0x2c0 net/core/skbuff.c:653
 alloc_skb include/linux/skbuff.h:1316 [inline]
 alloc_skb_with_frags+0xca/0x7b0 net/core/skbuff.c:6340
 sock_alloc_send_pskb+0x883/0x9a0 net/core/sock.c:2821
 unix_dgram_sendmsg+0x5a2/0x16d0 net/unix/af_unix.c:2003
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 sock_write_iter+0x2df/0x420 net/socket.c:1160
 do_iter_readv_writev fs/read_write.c:-1 [inline]
 do_iter_write+0x738/0xc30 fs/read_write.c:860
 vfs_writev fs/read_write.c:933 [inline]
 do_writev+0x27f/0x480 fs/read_write.c:976
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

The buggy address belongs to the object at ffff88807c987c00
 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 [ffff88807c987c00, ffff88807c987e00)

The buggy address belongs to the physical page:
page:ffffea0001f26100 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88807c986400 pfn:0x7c984
head:ffffea0001f26100 order:2 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000840 ffff888017c4f140 ffffea0001f2a610 ffffea0000b9bb10
raw: ffff88807c986400 0000000000100001 00000001ffffffff 0000000000000000
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 5143, tgid 5143 (udevd), ts 37752584564, free_ts 37391171454
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1c1/0x200 mm/page_alloc.c:1581
 prep_new_page mm/page_alloc.c:1588 [inline]
 get_page_from_freelist+0x1951/0x19e0 mm/page_alloc.c:3220
 __alloc_pages+0x1f0/0x460 mm/page_alloc.c:4500
 alloc_slab_page+0x5d/0x160 mm/slub.c:1881
 allocate_slab mm/slub.c:2028 [inline]
 new_slab+0x87/0x2d0 mm/slub.c:2081
 ___slab_alloc+0xc5d/0x12f0 mm/slub.c:3253
 __slab_alloc mm/slub.c:3339 [inline]
 __slab_alloc_node mm/slub.c:3392 [inline]
 slab_alloc_node mm/slub.c:3485 [inline]
 __kmem_cache_alloc_node+0x19e/0x250 mm/slub.c:3534
 __do_kmalloc_node mm/slab_common.c:1006 [inline]
 __kmalloc_node_track_caller+0xa2/0x230 mm/slab_common.c:1027
 kmalloc_reserve+0x116/0x240 net/core/skbuff.c:584
 __alloc_skb+0x138/0x2c0 net/core/skbuff.c:653
 alloc_skb include/linux/skbuff.h:1316 [inline]
 alloc_skb_with_frags+0xca/0x7b0 net/core/skbuff.c:6340
 sock_alloc_send_pskb+0x883/0x9a0 net/core/sock.c:2821
 unix_dgram_sendmsg+0x5a2/0x16d0 net/unix/af_unix.c:2003
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 sock_write_iter+0x2df/0x420 net/socket.c:1160
 call_write_iter include/linux/fs.h:2018 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x46c/0x990 fs/read_write.c:584
 ksys_write+0x150/0x260 fs/read_write.c:637
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1181 [inline]
 free_unref_page_prepare+0x7b2/0x8c0 mm/page_alloc.c:2365
 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2458
 discard_slab mm/slub.c:2127 [inline]
 __unfreeze_partials+0x1cf/0x210 mm/slub.c:2667
 put_cpu_partial+0x17c/0x250 mm/slub.c:2743
 __slab_free+0x319/0x400 mm/slub.c:3700
 qlink_free mm/kasan/quarantine.c:166 [inline]
 qlist_free_all+0x75/0xd0 mm/kasan/quarantine.c:185
 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:306
 kasan_slab_alloc include/linux/kasan.h:188 [inline]
 slab_post_alloc_hook+0x6e/0x4b0 mm/slab.h:767
 slab_alloc_node mm/slub.c:3495 [inline]
 kmem_cache_alloc_node+0x14c/0x320 mm/slub.c:3540
 __alloc_skb+0x103/0x2c0 net/core/skbuff.c:643
 alloc_skb include/linux/skbuff.h:1316 [inline]
 netlink_alloc_large_skb net/netlink/af_netlink.c:1184 [inline]
 netlink_sendmsg+0x66a/0xbf0 net/netlink/af_netlink.c:1869
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 ____sys_sendmsg+0x5ba/0x960 net/socket.c:2594
 ___sys_sendmsg+0x2a6/0x360 net/socket.c:2648
 __sys_sendmsg net/socket.c:2677 [inline]
 __do_sys_sendmsg net/socket.c:2686 [inline]
 __se_sys_sendmsg+0x1c2/0x2b0 net/socket.c:2684
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76

Memory state around the buggy address:
 ffff88807c987e80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88807c987f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88807c987f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                                                ^
 ffff88807c988000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88807c988080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
----------------
Code disassembly (best guess):
   0:	0f 84 33 01 00 00    	je     0x139
   6:	48 85 db             	test   %rbx,%rbx
   9:	0f 85 52 01 00 00    	jne    0x161
   f:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
  14:	4c 8b 75 d0          	mov    -0x30(%rbp),%r14
  18:	4c 89 e7             	mov    %r12,%rdi
  1b:	e8 e0 94 34 09       	call   0x9349500
  20:	e8 1b 2f 30 00       	call   0x302f40
  25:	fb                   	sti
  26:	4c 8b 65 c0          	mov    -0x40(%rbp),%r12
* 2a:	49 8d bc 24 f8 15 00 	lea    0x15f8(%r12),%rdi <-- trapping instruction
  31:	00
  32:	48 89 f8             	mov    %rdi,%rax
  35:	48 c1 e8 03          	shr    $0x3,%rax
  39:	42 0f b6 04 28       	movzbl (%rax,%r13,1),%eax
  3e:	84 c0                	test   %al,%al