==================================================================
BUG: KASAN: slab-out-of-bounds in mcp2221_raw_event+0x106a/0x1240 drivers/hid/hid-mcp2221.c:950
Read of size 1 at addr ffff88807cbbffff by task swapper/1/0
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xba/0x230 mm/kasan/report.c:482
kasan_report+0x117/0x150 mm/kasan/report.c:595
mcp2221_raw_event+0x106a/0x1240 drivers/hid/hid-mcp2221.c:950
__hid_input_report drivers/hid/hid-core.c:2140 [inline]
hid_input_report+0x41d/0x580 drivers/hid/hid-core.c:2167
hid_irq_in+0x47e/0x6d0 drivers/hid/usbhid/hid-core.c:286
__usb_hcd_giveback_urb+0x376/0x540 drivers/usb/core/hcd.c:1657
dummy_timer+0xbbd/0x45d0 drivers/usb/gadget/udc/dummy_hcd.c:1995
__run_hrtimer kernel/time/hrtimer.c:1785 [inline]
__hrtimer_run_queues+0x53a/0xcc0 kernel/time/hrtimer.c:1849
hrtimer_run_softirq+0x182/0x5a0 kernel/time/hrtimer.c:1866
handle_softirqs+0x22a/0x870 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0x5f/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+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:finish_task_switch+0x245/0x920 kernel/sched/core.c:5155
Code: 00 00 48 85 db 0f 85 e8 01 00 00 e9 56 05 00 00 4c 8b 75 d0 49 83 c4 48 4c 89 e7 e8 d5 a5 1c 0a e8 d0 8d 38 00 fb 4c 8b 65 c0 <49> 8d bc 24 80 16 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0
RSP: 0018:ffffc90000197bb8 EFLAGS: 00000202
RAX: 000000000016ad85 RBX: 0000000000000000 RCX: 0000000080000001
RDX: 0000000000000000 RSI: ffffffff8def9650 RDI: ffffffff8c27cb80
RBP: ffffc90000197c10 R08: ffffffff9011beb7 R09: 1ffffffff20237d6
R10: dffffc0000000000 R11: fffffbfff20237d7 R12: ffff88801d6c8000
R13: dffffc0000000000 R14: ffff888030ec3d00 R15: ffff8880b873b998
context_switch kernel/sched/core.c:5301 [inline]
__schedule+0x15e5/0x52d0 kernel/sched/core.c:6911
schedule_idle+0x51/0x90 kernel/sched/core.c:7034
do_idle+0x58a/0x5f0 kernel/sched/idle.c:381
cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:451
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x147
Allocated by task 6898:
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
unpoison_slab_object mm/kasan/common.c:340 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4538 [inline]
kmem_cache_alloc_bulk_noprof+0x570/0x7e0 mm/slub.c:7288
__io_alloc_req_refill+0xb4/0x360 io_uring/io_uring.c:965
io_alloc_req io_uring/io_uring.h:508 [inline]
io_submit_sqes+0x1011/0x2400 io_uring/io_uring.c:2032
__do_sys_io_uring_enter io_uring/io_uring.c:2604 [inline]
__se_sys_io_uring_enter+0x2cc/0x18c0 io_uring/io_uring.c:2539
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 23:
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2685 [inline]
slab_free_after_rcu_debug+0x126/0x220 mm/slub.c:6230
rcu_do_batch kernel/rcu/tree.c:2617 [inline]
rcu_core+0x7cd/0x1070 kernel/rcu/tree.c:2869
handle_softirqs+0x22a/0x870 kernel/softirq.c:622
run_ksoftirqd+0x36/0x60 kernel/softirq.c:1063
smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Last potentially related work creation:
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57
kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
slab_free_hook mm/slub.c:2646 [inline]
slab_free mm/slub.c:6165 [inline]
kmem_cache_free+0x426/0x630 mm/slub.c:6295
__io_req_caches_free+0x1c1/0x270 io_uring/io_uring.c:2134
io_req_caches_free+0x21/0x60 io_uring/io_uring.c:2146
io_ring_exit_work+0x41b/0x960 io_uring/io_uring.c:2340
process_one_work kernel/workqueue.c:3276 [inline]
process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
The buggy address belongs to the object at ffff88807cbbfdc0
which belongs to the cache io_kiocb of size 248
The buggy address is located 327 bytes to the right of
allocated 248-byte region [ffff88807cbbfdc0, ffff88807cbbfeb8)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7cbbf
memcg:ffff88807cbbff01
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88801f7368c0 dead000000000100 dead000000000122
raw: 0000000000000000 00000008000c000c 00000000f5000000 ffff88807cbbff01
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 6898, tgid 6897 (syz.2.271), ts 159697818864, free_ts 156126027726
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x231/0x280 mm/page_alloc.c:1889
prep_new_page mm/page_alloc.c:1897 [inline]
get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3962
__alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250
alloc_slab_page mm/slub.c:3292 [inline]
allocate_slab+0x77/0x660 mm/slub.c:3481
new_slab mm/slub.c:3539 [inline]
refill_objects+0x331/0x3c0 mm/slub.c:7175
__kmem_cache_alloc_bulk+0x3c/0x1a0 mm/slub.c:7212
kmem_cache_alloc_bulk_noprof+0x4d3/0x7e0 mm/slub.c:7264
__io_alloc_req_refill+0xb4/0x360 io_uring/io_uring.c:965
io_alloc_req io_uring/io_uring.h:508 [inline]
io_submit_sqes+0x1011/0x2400 io_uring/io_uring.c:2032
__do_sys_io_uring_enter io_uring/io_uring.c:2604 [inline]
__se_sys_io_uring_enter+0x2cc/0x18c0 io_uring/io_uring.c:2539
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 6856 tgid 6853 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1433 [inline]
__free_frozen_pages+0xc2b/0xdb0 mm/page_alloc.c:2978
free_image_page kernel/power/snapshot.c:267 [inline]
free_zone_bm_rtree kernel/power/snapshot.c:585 [inline]
memory_bm_free+0x2c1/0x4e0 kernel/power/snapshot.c:732
free_basic_memory_bitmaps+0x4f/0xd0 kernel/power/snapshot.c:1178
snapshot_release+0xe4/0x1d0 kernel/power/user.c:123
__fput+0x44f/0xa70 fs/file_table.c:469
task_work_run+0x1d9/0x270 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x70f/0x23c0 kernel/exit.c:976
do_group_exit+0x21b/0x2d0 kernel/exit.c:1118
get_signal+0x1284/0x1330 kernel/signal.c:3034
arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Memory state around the buggy address:
ffff88807cbbfe80: fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc
ffff88807cbbff00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88807cbbff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
^
ffff88807cbc0000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff88807cbc0080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
----------------
Code disassembly (best guess):
0: 00 00 add %al,(%rax)
2: 48 85 db test %rbx,%rbx
5: 0f 85 e8 01 00 00 jne 0x1f3
b: e9 56 05 00 00 jmp 0x566
10: 4c 8b 75 d0 mov -0x30(%rbp),%r14
14: 49 83 c4 48 add $0x48,%r12
18: 4c 89 e7 mov %r12,%rdi
1b: e8 d5 a5 1c 0a call 0xa1ca5f5
20: e8 d0 8d 38 00 call 0x388df5
25: fb sti
26: 4c 8b 65 c0 mov -0x40(%rbp),%r12
* 2a: 49 8d bc 24 80 16 00 lea 0x1680(%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