==================================================================
BUG: KASAN: slab-out-of-bounds in mcp2221_raw_event+0x1070/0x10a0 drivers/hid/hid-mcp2221.c:948
Read of size 1 at addr ffff8881291cbfff by task syz.4.4107/26025
CPU: 0 UID: 0 PID: 26025 Comm: syz.4.4107 Not tainted syzkaller #0 PREEMPT(voluntary)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xcd/0x630 mm/kasan/report.c:482
kasan_report+0xe0/0x110 mm/kasan/report.c:595
mcp2221_raw_event+0x1070/0x10a0 drivers/hid/hid-mcp2221.c:948
__hid_input_report.constprop.0+0x314/0x450 drivers/hid/hid-core.c:2139
hid_irq_in+0x35e/0x870 drivers/hid/usbhid/hid-core.c:286
__usb_hcd_giveback_urb+0x38b/0x610 drivers/usb/core/hcd.c:1661
usb_hcd_giveback_urb+0x39b/0x450 drivers/usb/core/hcd.c:1745
dummy_timer+0x1809/0x3a00 drivers/usb/gadget/udc/dummy_hcd.c:1995
__run_hrtimer kernel/time/hrtimer.c:1777 [inline]
__hrtimer_run_queues+0x1ff/0xad0 kernel/time/hrtimer.c:1841
hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1858
handle_softirqs+0x205/0x8d0 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xfa/0x160 kernel/softirq.c:723
irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
sysvec_apic_timer_interrupt+0x90/0xb0 arch/x86/kernel/apic/apic.c:1052
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:finish_task_switch.isra.0+0x1e9/0x9e0 kernel/sched/core.c:5193
Code: 0f 85 5f 07 00 00 8b 0d f9 a5 51 09 85 c9 0f 85 b9 02 00 00 48 89 df e8 a5 6e f7 05 e8 f0 09 37 00 fb 65 48 8b 1d 9f 6f 48 0b <48> 8d bb 50 15 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1
RSP: 0018:ffffc900024afd40 EFLAGS: 00000206
RAX: 0000000000000a55 RBX: ffff888113503a00 RCX: ffffffff8186395f
RDX: 0000000000000000 RSI: ffffffff88c86ff6 RDI: ffffffff878973c0
RBP: ffffc900024afd80 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff8aa0c9d7 R11: 0000000000000000 R12: ffff88813c7bd700
R13: 0000000000000000 R14: ffff8881f5838918 R15: ffff8881f5839418
context_switch kernel/sched/core.c:5328 [inline]
__schedule+0x1304/0x3b80 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7026
exit_to_user_mode_loop+0x5c/0xe0 kernel/entry/common.c:31
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x40f/0x4d0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbdcbdaeec9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffdcf84db28 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000001 RBX: 00007fbdcc005fa8 RCX: 00007fbdcbdaeec9
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007fbdcc005fa8
RBP: 0000000000000000 R08: 0000000000000001 R09: 00000006cf84de1f
R10: 00007fbdcc005fa0 R11: 0000000000000246 R12: 00007fbdcc005fac
R13: 00007fbdcc005fa0 R14: 0000000000001d8e R15: 0000000000000004
Allocated by task 2843:
kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
kasan_save_track+0x14/0x30 mm/kasan/common.c:77
poison_kmalloc_redzone mm/kasan/common.c:400 [inline]
__kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:417
kasan_kmalloc include/linux/kasan.h:262 [inline]
__do_kmalloc_node mm/slub.c:5603 [inline]
__kmalloc_node_track_caller_noprof+0x343/0x850 mm/slub.c:5712
kmalloc_reserve+0xef/0x2c0 net/core/skbuff.c:601
__alloc_skb+0x166/0x380 net/core/skbuff.c:670
alloc_skb include/linux/skbuff.h:1383 [inline]
alloc_skb_with_frags+0xe0/0x860 net/core/skbuff.c:6671
sock_alloc_send_pskb+0x7f9/0x980 net/core/sock.c:2965
unix_dgram_sendmsg+0x3e9/0x17f0 net/unix/af_unix.c:2153
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg net/socket.c:742 [inline]
__sys_sendto+0x4a3/0x520 net/socket.c:2244
__do_sys_sendto net/socket.c:2251 [inline]
__se_sys_sendto net/socket.c:2247 [inline]
__x64_sys_sendto+0xe0/0x1c0 net/socket.c:2247
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4d0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 2836:
kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
kasan_save_track+0x14/0x30 mm/kasan/common.c:77
__kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:587
kasan_save_free_info mm/kasan/kasan.h:406 [inline]
poison_slab_object mm/kasan/common.c:252 [inline]
__kasan_slab_free+0x43/0x70 mm/kasan/common.c:284
kasan_slab_free include/linux/kasan.h:234 [inline]
slab_free_hook mm/slub.c:2514 [inline]
slab_free mm/slub.c:6566 [inline]
kfree+0x288/0x670 mm/slub.c:6773
skb_kfree_head net/core/skbuff.c:1048 [inline]
skb_free_head+0x114/0x210 net/core/skbuff.c:1060
skb_release_data+0x795/0x9e0 net/core/skbuff.c:1087
skb_release_all net/core/skbuff.c:1152 [inline]
__kfree_skb net/core/skbuff.c:1166 [inline]
consume_skb net/core/skbuff.c:1398 [inline]
consume_skb+0xbf/0x100 net/core/skbuff.c:1392
__unix_dgram_recvmsg+0x779/0xc30 net/unix/af_unix.c:2683
unix_dgram_recvmsg+0xd0/0x110 net/unix/af_unix.c:2700
sock_recvmsg_nosec net/socket.c:1078 [inline]
sock_recvmsg+0x1f9/0x250 net/socket.c:1100
sock_read_iter+0x2b9/0x3b0 net/socket.c:1170
new_sync_read fs/read_write.c:491 [inline]
vfs_read+0xa95/0xcf0 fs/read_write.c:572
ksys_read+0x1f8/0x250 fs/read_write.c:715
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4d0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The buggy address belongs to the object at ffff8881291cbc00
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 [ffff8881291cbc00, ffff8881291cbe00)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1291c8
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff888111e32c01
flags: 0x200000000000040(head|node=0|zone=2)
page_type: f5(slab)
raw: 0200000000000040 ffff88810004b140 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000100010 00000000f5000000 ffff888111e32c01
head: 0200000000000040 ffff88810004b140 dead000000000122 0000000000000000
head: 0000000000000000 0000000000100010 00000000f5000000 ffff888111e32c01
head: 0200000000000002 ffffea0004a47201 00000000ffffffff 00000000ffffffff
head: 0000000000000000 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 2843, tgid 2843 (klogd), ts 2342321594547, free_ts 2333151949490
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1850
prep_new_page mm/page_alloc.c:1858 [inline]
get_page_from_freelist+0x1003/0x2dc0 mm/page_alloc.c:3884
__alloc_frozen_pages_noprof+0x259/0x21f0 mm/page_alloc.c:5183
alloc_pages_mpol+0xe4/0x410 mm/mempolicy.c:2416
alloc_slab_page mm/slub.c:3030 [inline]
allocate_slab mm/slub.c:3203 [inline]
new_slab+0x24a/0x360 mm/slub.c:3257
___slab_alloc+0xdb7/0x1a70 mm/slub.c:4627
__slab_alloc.constprop.0+0x63/0x110 mm/slub.c:4746
__slab_alloc_node mm/slub.c:4822 [inline]
slab_alloc_node mm/slub.c:5233 [inline]
__do_kmalloc_node mm/slub.c:5602 [inline]
__kmalloc_node_track_caller_noprof+0x4a5/0x850 mm/slub.c:5712
kmalloc_reserve+0xef/0x2c0 net/core/skbuff.c:601
__alloc_skb+0x166/0x380 net/core/skbuff.c:670
alloc_skb include/linux/skbuff.h:1383 [inline]
alloc_skb_with_frags+0xe0/0x860 net/core/skbuff.c:6671
sock_alloc_send_pskb+0x7f9/0x980 net/core/sock.c:2965
unix_dgram_sendmsg+0x3e9/0x17f0 net/unix/af_unix.c:2153
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg net/socket.c:742 [inline]
__sys_sendto+0x4a3/0x520 net/socket.c:2244
__do_sys_sendto net/socket.c:2251 [inline]
__se_sys_sendto net/socket.c:2247 [inline]
__x64_sys_sendto+0xe0/0x1c0 net/socket.c:2247
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4d0 arch/x86/entry/syscall_64.c:94
page last free pid 25317 tgid 25317 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1394 [inline]
__free_frozen_pages+0x78f/0x1000 mm/page_alloc.c:2906
vfree+0x1fd/0xb50 mm/vmalloc.c:3440
kcov_put kernel/kcov.c:439 [inline]
kcov_put kernel/kcov.c:435 [inline]
kcov_close+0x34/0x60 kernel/kcov.c:535
__fput+0x402/0xb70 fs/file_table.c:468
task_work_run+0x150/0x240 kernel/task_work.c:227
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x86f/0x2bf0 kernel/exit.c:966
do_group_exit+0xd3/0x2a0 kernel/exit.c:1107
get_signal+0x2671/0x26d0 kernel/signal.c:3034
arch_do_signal_or_restart+0x8f/0x7c0 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x76/0xe0 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x40f/0x4d0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Memory state around the buggy address:
ffff8881291cbe80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff8881291cbf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8881291cbf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
^
ffff8881291cc000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff8881291cc080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
----------------
Code disassembly (best guess):
0: 0f 85 5f 07 00 00 jne 0x765
6: 8b 0d f9 a5 51 09 mov 0x951a5f9(%rip),%ecx # 0x951a605
c: 85 c9 test %ecx,%ecx
e: 0f 85 b9 02 00 00 jne 0x2cd
14: 48 89 df mov %rbx,%rdi
17: e8 a5 6e f7 05 call 0x5f76ec1
1c: e8 f0 09 37 00 call 0x370a11
21: fb sti
22: 65 48 8b 1d 9f 6f 48 mov %gs:0xb486f9f(%rip),%rbx # 0xb486fc9
29: 0b
* 2a: 48 8d bb 50 15 00 00 lea 0x1550(%rbx),%rdi <-- trapping instruction
31: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
38: fc ff df
3b: 48 89 fa mov %rdi,%rdx
3e: 48 rex.W
3f: c1 .byte 0xc1