==================================================================
BUG: KASAN: use-after-free in mcp2221_raw_event+0x101c/0x1090 drivers/hid/hid-mcp2221.c:964
Read of size 1 at addr ffff88812f91bfff by task syz.2.4593/26204
CPU: 1 UID: 0 PID: 26204 Comm: syz.2.4593 Not tainted syzkaller #0 PREEMPT(lazy)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0x13d/0x4b0 mm/kasan/report.c:482
kasan_report+0xdf/0x1d0 mm/kasan/report.c:595
mcp2221_raw_event+0x101c/0x1090 drivers/hid/hid-mcp2221.c:964
__hid_input_report.constprop.0+0x319/0x470 drivers/hid/hid-core.c:2161
hid_irq_in+0x55d/0x710 drivers/hid/usbhid/hid-core.c:286
__usb_hcd_giveback_urb+0x38d/0x610 drivers/usb/core/hcd.c:1657
usb_hcd_giveback_urb+0x3ca/0x4a0 drivers/usb/core/hcd.c:1741
dummy_timer+0xda1/0x36c0 drivers/usb/gadget/udc/dummy_hcd.c:2005
__run_hrtimer kernel/time/hrtimer.c:1930 [inline]
__hrtimer_run_queues+0x470/0xa00 kernel/time/hrtimer.c:1994
hrtimer_run_softirq+0x17d/0x2c0 kernel/time/hrtimer.c:2011
handle_softirqs+0x1dd/0x9e0 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0x160/0x210 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+0x8f/0xb0 arch/x86/kernel/apic/apic.c:1061
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:198
Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 96 a8 1e fa 48 89 df e8 6e f8 1e fa f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 45 30 12 fa 65 8b 05 2e 0a 87 05 85 c0 74 16 5b
RSP: 0018:ffffc90002247bf8 EFLAGS: 00000246
RAX: 0000000000000002 RBX: ffff88810b700000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff890ca24b RDI: ffffffff87b08200
RBP: 0000000000000246 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000001
R13: ffff88810b7000b8 R14: ffff88810b7000b8 R15: ffff88811596f86c
spin_unlock_irqrestore include/linux/spinlock.h:408 [inline]
dummy_queue+0x3c5/0xb90 drivers/usb/gadget/udc/dummy_hcd.c:749
usb_ep_queue+0xfc/0x3c0 drivers/usb/gadget/udc/core.c:303
raw_process_ep_io+0x64d/0xc40 drivers/usb/gadget/legacy/raw_gadget.c:1114
raw_ioctl_ep_write drivers/usb/gadget/legacy/raw_gadget.c:1153 [inline]
raw_ioctl+0x25a/0x2b80 drivers/usb/gadget/legacy/raw_gadget.c:1325
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x10b/0x7f0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcb0c37caeb
Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00
RSP: 002b:00007fcb0add5f60 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007fcb0c37caeb
RDX: 00007fcb0add5fe0 RSI: 0000000040085507 RDI: 0000000000000003
RBP: 0000000000000003 R08: 00007fcb0c720320 R09: 0000000000000000
R10: 0000000000000003 R11: 0000000000000246 R12: 0000200000000140
R13: 0000000000000000 R14: 00007fcb0c5f5fa0 R15: 00007ffd9efa04f8
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x12f91b
flags: 0x200000000000000(node=0|zone=2)
page_type: f0(buddy)
raw: 0200000000000000 ffffea00047f0c88 ffffea0005128748 0000000000000000
raw: 0000000000000000 0000000000000000 00000000f0000000 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 0x2800(GFP_NOWAIT), pid 26085, tgid 26085 (syz.1.4572), ts 2920235311562, free_ts 2920449309398
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1853
prep_new_page mm/page_alloc.c:1861 [inline]
get_page_from_freelist+0x20a5/0x3850 mm/page_alloc.c:3941
__alloc_frozen_pages_noprof+0x273/0x28a0 mm/page_alloc.c:5221
alloc_pages_mpol+0xe8/0x410 mm/mempolicy.c:2490
alloc_pages_noprof+0x1a/0x160 mm/mempolicy.c:2581
get_free_pages_noprof+0x10/0xb0 mm/page_alloc.c:5280
tlb_next_batch mm/mmu_gather.c:37 [inline]
__tlb_remove_folio_pages_size.isra.0+0x2dc/0x550 mm/mmu_gather.c:198
zap_present_folio_ptes mm/memory.c:1677 [inline]
zap_present_ptes mm/memory.c:1730 [inline]
do_zap_pte_range mm/memory.c:1832 [inline]
zap_pte_range mm/memory.c:1934 [inline]
zap_pmd_range mm/memory.c:2020 [inline]
zap_pud_range mm/memory.c:2048 [inline]
zap_p4d_range mm/memory.c:2069 [inline]
__zap_vma_range+0x12f7/0x4090 mm/memory.c:2109
unmap_vmas+0x299/0x5f0 mm/memory.c:2178
exit_mmap+0x1ef/0xa10 mm/mmap.c:1300
__mmput kernel/fork.c:1178 [inline]
mmput+0xe0/0x430 kernel/fork.c:1201
exit_mm kernel/exit.c:582 [inline]
do_exit+0x8b2/0x2af0 kernel/exit.c:964
do_group_exit+0xd5/0x2a0 kernel/exit.c:1119
get_signal+0x20ff/0x2210 kernel/signal.c:3037
arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
exit_to_user_mode_loop+0x83/0x480 kernel/entry/common.c:98
page last free pid 26085 tgid 26085 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1397 [inline]
__free_frozen_pages+0x6d8/0xf60 mm/page_alloc.c:2938
tlb_batch_list_free mm/mmu_gather.c:161 [inline]
tlb_finish_mmu+0x27d/0x810 mm/mmu_gather.c:552
exit_mmap+0x454/0xa10 mm/mmap.c:1313
__mmput kernel/fork.c:1178 [inline]
mmput+0xe0/0x430 kernel/fork.c:1201
exit_mm kernel/exit.c:582 [inline]
do_exit+0x8b2/0x2af0 kernel/exit.c:964
do_group_exit+0xd5/0x2a0 kernel/exit.c:1119
get_signal+0x20ff/0x2210 kernel/signal.c:3037
arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
exit_to_user_mode_loop+0x83/0x480 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+0x682/0x7f0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Memory state around the buggy address:
ffff88812f91be80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff88812f91bf00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88812f91bf80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
^
ffff88812f91c000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff88812f91c080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
----------------
Code disassembly (best guess):
0: f5 cmc
1: 53 push %rbx
2: 48 8b 74 24 10 mov 0x10(%rsp),%rsi
7: 48 89 fb mov %rdi,%rbx
a: 48 83 c7 18 add $0x18,%rdi
e: e8 96 a8 1e fa call 0xfa1ea8a9
13: 48 89 df mov %rbx,%rdi
16: e8 6e f8 1e fa call 0xfa1ef889
1b: f7 c5 00 02 00 00 test $0x200,%ebp
21: 75 23 jne 0x46
23: 9c pushf
24: 58 pop %rax
25: f6 c4 02 test $0x2,%ah
28: 75 37 jne 0x61
* 2a: bf 01 00 00 00 mov $0x1,%edi <-- trapping instruction
2f: e8 45 30 12 fa call 0xfa123079
34: 65 8b 05 2e 0a 87 05 mov %gs:0x5870a2e(%rip),%eax # 0x5870a69
3b: 85 c0 test %eax,%eax
3d: 74 16 je 0x55
3f: 5b pop %rbx