==================================================================
BUG: KASAN: slab-out-of-bounds in mcp2221_raw_event+0x10b0/0x12a0 drivers/hid/hid-mcp2221.c:964
Read of size 1 at addr ffff88807830ffff by task kdevtmpfs/26
CPU: 0 UID: 0 PID: 26 Comm: kdevtmpfs Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
print_address_description+0x55/0x1e0 mm/kasan/report.c:378
print_report+0x58/0x70 mm/kasan/report.c:482
kasan_report+0x117/0x150 mm/kasan/report.c:595
mcp2221_raw_event+0x10b0/0x12a0 drivers/hid/hid-mcp2221.c:964
__hid_input_report+0x428/0x590 drivers/hid/hid-core.c:2161
hid_irq_in+0x495/0x710 drivers/hid/usbhid/hid-core.c:286
__usb_hcd_giveback_urb+0x376/0x540 drivers/usb/core/hcd.c:1655
dummy_timer+0xbc0/0x4650 drivers/usb/gadget/udc/dummy_hcd.c:2005
__run_hrtimer kernel/time/hrtimer.c:1930 [inline]
__hrtimer_run_queues+0x3c0/0xa20 kernel/time/hrtimer.c:1994
hrtimer_run_softirq+0x17a/0x240 kernel/time/hrtimer.c:2011
handle_softirqs+0x22a/0x840 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xca/0x220 kernel/softirq.c:735
irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1061
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:unwind_next_frame+0xf08/0x2550 arch/x86/kernel/unwind_orc.c:619
Code: 00 00 00 fc ff df 48 8b 44 24 30 80 3c 28 00 4c 8b 7c 24 10 74 08 4c 89 ff e8 74 1f ba 00 49 89 1f 48 8b 44 24 58 80 3c 28 00 <48> 8b 5c 24 78 4c 8b 64 24 18 74 08 48 89 df e8 54 1f ba 00 4c 89
RSP: 0018:ffffc90000a174f8 EFLAGS: 00000246
RAX: 1ffff92000142ec0 RBX: ffffffff8230dd4c RCX: 1ffff92000142e01
RDX: ffffffff90d24d2a RSI: 0000000000000002 RDI: ffffc90000a17930
RBP: dffffc0000000000 R08: 000000000000000c R09: ffffffff8e95cc20
R10: ffffc90000a17618 R11: ffffffff81b0e0e0 R12: ffffc90000a18000
R13: 1ffff92000142ebb R14: ffffc90000a175c8 R15: ffffc90000a17610
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
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:4570 [inline]
slab_alloc_node mm/slub.c:4899 [inline]
kmem_cache_alloc_lru_noprof+0x2b8/0x640 mm/slub.c:4918
__d_alloc+0x37/0x6f0 fs/dcache.c:1807
d_alloc+0x4b/0x190 fs/dcache.c:1886
lookup_one_qstr_excl+0xd8/0x360 fs/namei.c:1801
__start_dirop fs/namei.c:2916 [inline]
start_dirop fs/namei.c:2938 [inline]
filename_create+0x20e/0x370 fs/namei.c:4950
start_creating_path+0x39/0x150 fs/namei.c:4973
handle_create drivers/base/devtmpfs.c:224 [inline]
handle drivers/base/devtmpfs.c:384 [inline]
devtmpfs_work_loop+0x1fc/0xdf0 drivers/base/devtmpfs.c:399
devtmpfsd+0x4d/0x50 drivers/base/devtmpfs.c:441
kthread+0x389/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Allocated by task 28470:
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:4570 [inline]
slab_alloc_node mm/slub.c:4899 [inline]
kmem_cache_alloc_noprof+0x2bc/0x650 mm/slub.c:4906
kmem_alloc_batch lib/debugobjects.c:371 [inline]
fill_pool+0x156/0x580 lib/debugobjects.c:420
debug_objects_fill_pool lib/debugobjects.c:752 [inline]
debug_object_assert_init+0x367/0x3b0 lib/debugobjects.c:1030
debug_hrtimer_assert_init kernel/time/hrtimer.c:495 [inline]
hrtimer_start_range_ns+0x3f/0xed0 kernel/time/hrtimer.c:1477
hrtimer_start include/linux/hrtimer.h:220 [inline]
hrtick_cond_restart kernel/sched/core.c:924 [inline]
hrtick_schedule_exit kernel/sched/core.c:986 [inline]
finish_lock_switch kernel/sched/core.c:5124 [inline]
finish_task_switch+0x3cd/0xbe0 kernel/sched/core.c:5243
context_switch kernel/sched/core.c:5391 [inline]
__schedule+0x1829/0x5740 kernel/sched/core.c:7189
preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7370
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline]
_raw_spin_unlock_irqrestore+0x74/0x80 kernel/locking/spinlock.c:198
rcu_report_unblock_qs_rnp kernel/rcu/tree.c:2426 [inline]
rcu_preempt_deferred_qs_irqrestore+0x906/0xbc0 kernel/rcu/tree_plugin.h:571
__rcu_read_unlock+0x83/0xe0 kernel/rcu/tree_plugin.h:438
rcu_read_unlock include/linux/rcupdate.h:871 [inline]
class_rcu_destructor include/linux/rcupdate.h:1181 [inline]
unwind_next_frame+0x1bbf/0x2550 arch/x86/kernel/unwind_orc.c:709
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
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:4570 [inline]
slab_alloc_node mm/slub.c:4899 [inline]
kmem_cache_alloc_lru_noprof+0x2b8/0x640 mm/slub.c:4918
alloc_inode+0x6a/0x1b0 fs/inode.c:345
new_inode+0x22/0x170 fs/inode.c:1179
debugfs_get_inode fs/debugfs/inode.c:72 [inline]
__debugfs_create_file+0xb8/0x400 fs/debugfs/inode.c:433
debugfs_create_file_full+0x3f/0x60 fs/debugfs/inode.c:460
kvm_create_vm_debugfs+0x6ec/0x8f0 virt/kvm/kvm_main.c:1057
kvm_create_vm virt/kvm/kvm_main.c:1196 [inline]
kvm_dev_ioctl_create_vm virt/kvm/kvm_main.c:5492 [inline]
kvm_dev_ioctl+0x11ce/0x1590 virt/kvm/kvm_main.c:5534
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The buggy address belongs to the object at ffff88807830ffc0
which belongs to the cache debug_objects_cache of size 40
The buggy address is located 23 bytes to the right of
allocated 40-byte region [ffff88807830ffc0, ffff88807830ffe8)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7830f
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88813fe338c0 dead000000000100 dead000000000122
raw: 0000000000000000 0000000800490049 00000000f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x1c2100(__GFP_ZERO|__GFP_NOWARN|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 28470, tgid 28469 (syz.0.7035), ts 1382190618043, free_ts 1341316213551
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x22d/0x280 mm/page_alloc.c:1853
prep_new_page mm/page_alloc.c:1861 [inline]
get_page_from_freelist+0x2593/0x2610 mm/page_alloc.c:3941
alloc_frozen_pages_nolock_noprof+0xac/0x140 mm/page_alloc.c:7757
alloc_slab_page mm/slub.c:3273 [inline]
allocate_slab+0xf2/0x660 mm/slub.c:3467
new_slab mm/slub.c:3525 [inline]
___slab_alloc+0x154/0x6c0 mm/slub.c:4445
__slab_alloc_node mm/slub.c:4511 [inline]
slab_alloc_node mm/slub.c:4887 [inline]
kmem_cache_alloc_noprof+0x12d/0x650 mm/slub.c:4906
kmem_alloc_batch lib/debugobjects.c:371 [inline]
fill_pool+0x156/0x580 lib/debugobjects.c:420
debug_objects_fill_pool lib/debugobjects.c:752 [inline]
debug_object_assert_init+0x367/0x3b0 lib/debugobjects.c:1030
debug_hrtimer_assert_init kernel/time/hrtimer.c:495 [inline]
hrtimer_start_range_ns+0x3f/0xed0 kernel/time/hrtimer.c:1477
hrtimer_start include/linux/hrtimer.h:220 [inline]
hrtick_cond_restart kernel/sched/core.c:924 [inline]
hrtick_schedule_exit kernel/sched/core.c:986 [inline]
finish_lock_switch kernel/sched/core.c:5124 [inline]
finish_task_switch+0x3cd/0xbe0 kernel/sched/core.c:5243
context_switch kernel/sched/core.c:5391 [inline]
__schedule+0x1829/0x5740 kernel/sched/core.c:7189
preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7370
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline]
_raw_spin_unlock_irqrestore+0x74/0x80 kernel/locking/spinlock.c:198
rcu_report_unblock_qs_rnp kernel/rcu/tree.c:2426 [inline]
rcu_preempt_deferred_qs_irqrestore+0x906/0xbc0 kernel/rcu/tree_plugin.h:571
__rcu_read_unlock+0x83/0xe0 kernel/rcu/tree_plugin.h:438
page last free pid 27683 tgid 27682 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1397 [inline]
free_unref_folios+0xd9f/0x14c0 mm/page_alloc.c:2999
folios_put_refs+0x9ff/0xb40 mm/swap.c:1008
folio_batch_release include/linux/folio_batch.h:101 [inline]
truncate_inode_pages_range+0x3dd/0xe30 mm/truncate.c:408
evict+0x631/0xb10 fs/inode.c:843
__dentry_kill+0x1a2/0x690 fs/dcache.c:718
shrink_kill+0xa9/0x2c0 fs/dcache.c:1195
shrink_dentry_list+0x2e0/0x5e0 fs/dcache.c:1222
shrink_dcache_tree+0xe9/0x5d0 fs/dcache.c:-1
do_one_tree fs/dcache.c:1721 [inline]
shrink_dcache_for_umount+0xa8/0x1f0 fs/dcache.c:1738
generic_shutdown_super+0x6f/0x2d0 fs/super.c:624
kill_anon_super+0x3b/0x70 fs/super.c:1292
deactivate_locked_super+0xbc/0x130 fs/super.c:476
cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312
task_work_run+0x1d9/0x270 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x70f/0x22c0 kernel/exit.c:976
do_group_exit+0x21b/0x2d0 kernel/exit.c:1119
Memory state around the buggy address:
ffff88807830fe80: 00 00 00 fc fc 00 00 00 00 00 fc fc 00 00 00 00
ffff88807830ff00: 00 fc fc 00 00 00 00 00 fc fc 00 00 00 00 00 fc
>ffff88807830ff80: fc 00 00 00 00 00 fc fc 00 00 00 00 00 fc fc fc
^
ffff888078310000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff888078310080: 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: 00 fc add %bh,%ah
4: ff lcall (bad)
5: df 48 8b fisttps -0x75(%rax)
8: 44 24 30 rex.R and $0x30,%al
b: 80 3c 28 00 cmpb $0x0,(%rax,%rbp,1)
f: 4c 8b 7c 24 10 mov 0x10(%rsp),%r15
14: 74 08 je 0x1e
16: 4c 89 ff mov %r15,%rdi
19: e8 74 1f ba 00 call 0xba1f92
1e: 49 89 1f mov %rbx,(%r15)
21: 48 8b 44 24 58 mov 0x58(%rsp),%rax
26: 80 3c 28 00 cmpb $0x0,(%rax,%rbp,1)
* 2a: 48 8b 5c 24 78 mov 0x78(%rsp),%rbx <-- trapping instruction
2f: 4c 8b 64 24 18 mov 0x18(%rsp),%r12
34: 74 08 je 0x3e
36: 48 89 df mov %rbx,%rdi
39: e8 54 1f ba 00 call 0xba1f92
3e: 4c rex.WR
3f: 89 .byte 0x89