==================================================================
BUG: KASAN: use-after-free in mcp2221_raw_event+0x106a/0x1240 drivers/hid/hid-mcp2221.c:957
Read of size 1 at addr ffff888055e4ffff by task syz.4.697/8533
CPU: 0 UID: 0 PID: 8533 Comm: syz.4.697 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
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+0x106a/0x1240 drivers/hid/hid-mcp2221.c:957
__hid_input_report drivers/hid/hid-core.c:2139 [inline]
hid_input_report+0x41d/0x580 drivers/hid/hid-core.c:2166
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+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:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x47/0x80 kernel/locking/spinlock.c:198
Code: f7 e8 bd fd e5 f5 f7 c3 00 02 00 00 74 05 e8 60 69 11 f6 9c 58 a9 00 02 00 00 75 27 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 b4 96 d7 f5 65 8b 05 dd a7 84 07 85 c0 74 18 5b 41 5e e9 41 48
RSP: 0018:ffffc90003f1fa08 EFLAGS: 00000206
RAX: 0000000000000006 RBX: 0000000000000283 RCX: 0000000080000001
RDX: 0000000000000000 RSI: ffffffff8e106c7e RDI: 0000000000000001
RBP: ffffc90003f1fb70 R08: ffffffff9033bef7 R09: 1ffffffff20677de
R10: dffffc0000000000 R11: fffffbfff20677df R12: dffffc0000000000
R13: 1ffff920007e3f50 R14: ffff8880330f6008 R15: 0000000000000001
spin_unlock_irqrestore include/linux/spinlock.h:408 [inline]
raw_process_ep_io+0x293/0xd90 drivers/usb/gadget/legacy/raw_gadget.c:1140
raw_ioctl_ep_write drivers/usb/gadget/legacy/raw_gadget.c:1153 [inline]
raw_ioctl+0x252c/0x41c0 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+0xfc/0x170 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f678df9c4ab
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:00007f678eefdf60 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f678df9c4ab
RDX: 00007f678eefdfe0 RSI: 0000000040085507 RDI: 0000000000000003
RBP: 0000000000000003 R08: 00007f678e340320 R09: 0000000000000000
R10: 0000000000000003 R11: 0000000000000246 R12: 0000200000000140
R13: 0000000000000000 R14: 00007f678e215fa0 R15: 00007fffad72a358
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888000000000 pfn:0x55e4f
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 dead000000000100 dead000000000122 0000000000000000
raw: ffff888000000000 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 0x440dc0(GFP_KERNEL_ACCOUNT|__GFP_ZERO|__GFP_COMP), pid 7061, tgid 7058 (syz.3.315), ts 157223521172, free_ts 157660662804
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x231/0x280 mm/page_alloc.c:1858
prep_new_page mm/page_alloc.c:1866 [inline]
get_page_from_freelist+0x24ba/0x2540 mm/page_alloc.c:3946
__alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5226
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
pagetable_alloc_noprof include/linux/mm.h:3651 [inline]
pmd_alloc_one_noprof include/asm-generic/pgalloc.h:143 [inline]
__pmd_alloc+0x3a/0x5c0 mm/memory.c:6847
pmd_alloc include/linux/mm.h:3567 [inline]
copy_pmd_range+0x5552/0x5970 mm/memory.c:1372
copy_pud_range mm/memory.c:1429 [inline]
copy_p4d_range mm/memory.c:1453 [inline]
copy_page_range+0xbe8/0x11f0 mm/memory.c:1539
dup_mmap+0xf40/0x1d90 mm/mmap.c:1840
dup_mm kernel/fork.c:1534 [inline]
copy_mm+0x13b/0x4a0 kernel/fork.c:1586
copy_process+0x1efd/0x4430 kernel/fork.c:2261
kernel_clone+0x2d7/0x940 kernel/fork.c:2723
__do_sys_clone kernel/fork.c:2864 [inline]
__se_sys_clone kernel/fork.c:2848 [inline]
__x64_sys_clone+0x1b6/0x230 kernel/fork.c:2848
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 7078 tgid 7078 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1402 [inline]
__free_frozen_pages+0xbc7/0xd30 mm/page_alloc.c:2943
__tlb_remove_table_free mm/mmu_gather.c:228 [inline]
tlb_remove_table_rcu+0x85/0x100 mm/mmu_gather.c:291
rcu_do_batch kernel/rcu/tree.c:2617 [inline]
rcu_core+0x7cd/0x1070 kernel/rcu/tree.c:2869
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
Memory state around the buggy address:
ffff888055e4fe80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff888055e4ff00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888055e4ff80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
^
ffff888055e50000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff888055e50080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
----------------
Code disassembly (best guess):
0: f7 e8 imul %eax
2: bd fd e5 f5 f7 mov $0xf7f5e5fd,%ebp
7: c3 ret
8: 00 02 add %al,(%rdx)
a: 00 00 add %al,(%rax)
c: 74 05 je 0x13
e: e8 60 69 11 f6 call 0xf6116973
13: 9c pushf
14: 58 pop %rax
15: a9 00 02 00 00 test $0x200,%eax
1a: 75 27 jne 0x43
1c: f7 c3 00 02 00 00 test $0x200,%ebx
22: 74 01 je 0x25
24: fb sti
25: bf 01 00 00 00 mov $0x1,%edi
* 2a: e8 b4 96 d7 f5 call 0xf5d796e3 <-- trapping instruction
2f: 65 8b 05 dd a7 84 07 mov %gs:0x784a7dd(%rip),%eax # 0x784a813
36: 85 c0 test %eax,%eax
38: 74 18 je 0x52
3a: 5b pop %rbx
3b: 41 5e pop %r14
3d: e9 .byte 0xe9
3e: 41 rex.B
3f: 48 rex.W