==================================================================
BUG: KASAN: use-after-free in mcp2221_raw_event+0x10b0/0x12a0 drivers/hid/hid-mcp2221.c:964
Read of size 1 at addr ffff88809b523fff by task syz.4.5628/28350
CPU: 1 UID: 0 PID: 28350 Comm: syz.4.5628 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:lock_release+0x2dc/0x3c0 kernel/locking/lockdep.c:5893
Code: 00 00 eb b5 e8 95 7d 05 0a f7 c3 00 02 00 00 74 b9 65 48 8b 05 75 68 96 11 48 3b 44 24 28 75 44 fb 48 83 c4 30 5b 41 5c 41 5d <41> 5e 41 5f 5d e9 1a 72 08 0a cc 48 8d 3d f2 b3 91 0e 67 48 0f b9
RSP: 0018:ffffc90004e8fba8 EFLAGS: 00000286
RAX: 2beff49d83a5f400 RBX: ffff8880560e0000 RCX: 0000000000000046
RDX: 0000000000000000 RSI: ffffffff8e2168c0 RDI: ffffffff8c28b760
RBP: ffff8880560e0b90 R08: ffffffff8ba88590 R09: ffffffff8e812880
R10: dffffc0000000000 R11: fffffbfff206053f R12: ffff8880560e002c
R13: dffffc0000000000 R14: ffffffff8e812880 R15: ffff8880560e0000
sched_submit_work kernel/sched/core.c:7249 [inline]
schedule+0x141/0x360 kernel/sched/core.c:7282
do_nanosleep+0x1c2/0x620 kernel/time/hrtimer.c:2293
hrtimer_nanosleep+0x18f/0x3a0 kernel/time/hrtimer.c:2339
__do_sys_clock_nanosleep kernel/time/posix-timers.c:1391 [inline]
__se_sys_clock_nanosleep+0x35b/0x3b0 kernel/time/posix-timers.c:1368
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
RIP: 0033:0x7faed255d68e
Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08
RSP: 002b:00007faed07f4f38 EFLAGS: 00000246 ORIG_RAX: 00000000000000e6
RAX: ffffffffffffffda RBX: 00007faed07f66c0 RCX: 00007faed255d68e
RDX: 00007faed07f4f90 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00002000000006c0
R13: 0000000000000000 R14: 00007faed2815fa0 R15: 00007faed293fa48
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x200000019 pfn:0x9b523
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 dead000000000100 dead000000000122 0000000000000000
raw: 0000000200000019 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x500cc0(GFP_USER|__GFP_ACCOUNT), pid 28088, tgid 28086 (syz.5.5560), ts 1412801361190, free_ts 1415891654493
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_noprof+0x18d/0x380 mm/page_alloc.c:5221
alloc_pages_mpol+0x235/0x490 mm/mempolicy.c:2490
alloc_frozen_pages_noprof mm/mempolicy.c:2561 [inline]
alloc_pages_noprof+0xac/0x2a0 mm/mempolicy.c:2581
get_free_pages_noprof+0xf/0x80 mm/page_alloc.c:5280
mmu_memory_cache_alloc_obj virt/kvm/kvm_main.c:358 [inline]
__kvm_mmu_topup_memory_cache+0x24f/0x610 virt/kvm/kvm_main.c:395
mmu_topup_memory_caches+0xd6/0x170 arch/x86/kvm/mmu/mmu.c:611
kvm_mmu_load+0x9d/0x22d0 arch/x86/kvm/mmu/mmu.c:6075
kvm_mmu_reload arch/x86/kvm/mmu.h:123 [inline]
vcpu_enter_guest arch/x86/kvm/x86.c:11370 [inline]
vcpu_run+0x5c84/0x7860 arch/x86/kvm/x86.c:11770
kvm_arch_vcpu_ioctl_run+0x11e6/0x20d0 arch/x86/kvm/x86.c:12125
kvm_vcpu_ioctl+0xa62/0xfd0 virt/kvm/kvm_main.c:4469
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
page last free pid 28088 tgid 28086 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1397 [inline]
__free_frozen_pages+0xc1c/0xd30 mm/page_alloc.c:2938
kvm_mmu_free_memory_cache+0x11a/0x240 virt/kvm/kvm_main.c:419
mmu_free_memory_caches arch/x86/kvm/mmu/mmu.c:628 [inline]
kvm_mmu_destroy+0x336/0x390 arch/x86/kvm/mmu/mmu.c:7655
kvm_arch_vcpu_destroy+0x28e/0x380 arch/x86/kvm/x86.c:12974
kvm_vcpu_destroy virt/kvm/kvm_main.c:468 [inline]
kvm_destroy_vcpus+0x123/0x380 virt/kvm/kvm_main.c:488
kvm_arch_destroy_vm+0xf9/0x2d0 arch/x86/kvm/x86.c:13524
kvm_destroy_vm virt/kvm/kvm_main.c:1294 [inline]
kvm_put_kvm+0x6ca/0xa50 virt/kvm/kvm_main.c:1331
kvm_vm_release+0x43/0x50 virt/kvm/kvm_main.c:1354
__fput+0x44f/0xa60 fs/file_table.c:510
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
get_signal+0x1284/0x1330 kernel/signal.c:3037
arch_do_signal_or_restart+0xbc/0x840 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
exit_to_user_mode_loop+0xa9/0x680 kernel/entry/common.c:98
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100
Memory state around the buggy address:
ffff88809b523e80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff88809b523f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88809b523f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
^
ffff88809b524000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff88809b524080: 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: eb b5 jmp 0xffffffb9
4: e8 95 7d 05 0a call 0xa057d9e
9: f7 c3 00 02 00 00 test $0x200,%ebx
f: 74 b9 je 0xffffffca
11: 65 48 8b 05 75 68 96 mov %gs:0x11966875(%rip),%rax # 0x1196688e
18: 11
19: 48 3b 44 24 28 cmp 0x28(%rsp),%rax
1e: 75 44 jne 0x64
20: fb sti
21: 48 83 c4 30 add $0x30,%rsp
25: 5b pop %rbx
26: 41 5c pop %r12
28: 41 5d pop %r13
* 2a: 41 5e pop %r14 <-- trapping instruction
2c: 41 5f pop %r15
2e: 5d pop %rbp
2f: e9 1a 72 08 0a jmp 0xa08724e
34: cc int3
35: 48 8d 3d f2 b3 91 0e lea 0xe91b3f2(%rip),%rdi # 0xe91b42e
3c: 67 addr32
3d: 48 rex.W
3e: 0f .byte 0xf
3f: b9 .byte 0xb9