==================================================================
BUG: KASAN: use-after-free in mcp2221_raw_event+0x103c/0x10a0 drivers/hid/hid-mcp2221.c:948
Read of size 1 at addr ffff888128b97fff by task kworker/0:1/10
CPU: 0 UID: 0 PID: 10 Comm: kworker/0:1 Not tainted syzkaller #0 PREEMPT(voluntary)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: usb_hub_wq hub_event
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+0x156/0x4c9 mm/kasan/report.c:482
kasan_report+0xdf/0x1a0 mm/kasan/report.c:595
mcp2221_raw_event+0x103c/0x10a0 drivers/hid/hid-mcp2221.c:948
__hid_input_report.constprop.0+0x314/0x460 drivers/hid/hid-core.c:2139
hid_irq_in+0x52e/0x6b0 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+0xd85/0x3670 drivers/usb/gadget/udc/dummy_hcd.c:1995
__run_hrtimer kernel/time/hrtimer.c:1777 [inline]
__hrtimer_run_queues+0x516/0x990 kernel/time/hrtimer.c:1841
hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1858
handle_softirqs+0x1dd/0x8f0 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xed/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+0x8f/0xb0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:find_stack lib/stackdepot.c:602 [inline]
RIP: 0010:stack_depot_save_flags+0x192/0x9c0 lib/stackdepot.c:668
Code: f8 09 49 8b 0e 49 39 ce 75 1a e9 ab 00 00 00 66 0f 1f 84 00 00 00 00 00 48 8b 09 49 39 ce 0f 84 22 02 00 00 44 39 49 10 75 ee <44> 3b 79 14 75 e8 31 c0 66 66 2e 0f 1f 84 00 00 00 00 00 66 66 2e
RSP: 0018:ffffc900000af4f0 EFLAGS: 00000246
RAX: 0000000009f12d79 RBX: 0000000000000001 RCX: ffff88811a525760
RDX: ffffffff815939aa RSI: 00000000cd3f5f01 RDI: 0000000000000003
RBP: 0000000000000c00 R08: 00000000002a2680 R09: 00000000ae62a268
R10: 0000000000000200 R11: 0000000000005939 R12: ffffc900000af548
R13: 000000000000000c R14: ffff8881f3ca2680 R15: 000000000000000c
kasan_save_stack+0x3f/0x50 mm/kasan/common.c:58
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
__kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:415
kmalloc_noprof include/linux/slab.h:957 [inline]
usb_control_msg+0xbc/0x4a0 drivers/usb/core/message.c:144
get_bMaxPacketSize0+0xf0/0x2b0 drivers/usb/core/hub.c:4851
hub_port_init+0xc2d/0x3810 drivers/usb/core/hub.c:5112
hub_port_connect drivers/usb/core/hub.c:5496 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
port_event drivers/usb/core/hub.c:5871 [inline]
hub_event+0x2f27/0x4af0 drivers/usb/core/hub.c:5953
process_one_work+0x9c2/0x1840 kernel/workqueue.c:3257
process_scheduled_works kernel/workqueue.c:3340 [inline]
worker_thread+0x5da/0xe40 kernel/workqueue.c:3421
kthread+0x3b3/0x730 kernel/kthread.c:463
ret_from_fork+0x6c3/0xa20 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888128b97cc0 pfn:0x128b97
flags: 0x200000000000000(node=0|zone=2)
raw: 0200000000000000 dead000000000100 dead000000000122 0000000000000000
raw: ffff888128b97cc0 ffff888124949180 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 10354, tgid 10354 (syz-executor), ts 1751487943723, free_ts 1755841642488
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1e1/0x250 mm/page_alloc.c:1884
prep_new_page mm/page_alloc.c:1892 [inline]
get_page_from_freelist+0xd57/0x3b20 mm/page_alloc.c:3945
__alloc_frozen_pages_noprof+0x269/0x2230 mm/page_alloc.c:5240
alloc_pages_mpol+0xe8/0x410 mm/mempolicy.c:2486
alloc_frozen_pages_noprof mm/mempolicy.c:2557 [inline]
alloc_pages_noprof+0x131/0x390 mm/mempolicy.c:2577
pagetable_alloc_noprof include/linux/mm.h:3190 [inline]
__pte_alloc_one_noprof include/asm-generic/pgalloc.h:76 [inline]
pte_alloc_one+0x1e/0x3e0 arch/x86/mm/pgtable.c:18
__pte_alloc+0x6d/0x3f0 mm/memory.c:453
copy_pte_range mm/memory.c:1237 [inline]
copy_pmd_range mm/memory.c:1392 [inline]
copy_pud_range mm/memory.c:1429 [inline]
copy_p4d_range mm/memory.c:1453 [inline]
copy_page_range+0x1605/0x25e0 mm/memory.c:1535
dup_mmap+0xbb3/0x1c30 mm/mmap.c:1827
dup_mm kernel/fork.c:1529 [inline]
copy_mm kernel/fork.c:1581 [inline]
copy_process+0x718c/0x77a0 kernel/fork.c:2221
kernel_clone+0xfc/0x930 kernel/fork.c:2651
__do_sys_clone+0xd9/0x120 kernel/fork.c:2792
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xc9/0x570 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 6381 tgid 6381 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1433 [inline]
__free_frozen_pages+0x7d1/0x1010 mm/page_alloc.c:2973
__pagetable_free include/linux/mm.h:3200 [inline]
pagetable_free include/linux/mm.h:3224 [inline]
pagetable_dtor_free include/linux/mm.h:3328 [inline]
__tlb_remove_table include/asm-generic/tlb.h:220 [inline]
__tlb_remove_table_free mm/mmu_gather.c:227 [inline]
tlb_remove_table_rcu+0x2b2/0x390 mm/mmu_gather.c:290
rcu_do_batch kernel/rcu/tree.c:2605 [inline]
rcu_core+0x7c0/0x15c0 kernel/rcu/tree.c:2857
handle_softirqs+0x1dd/0x8f0 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xed/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+0x8f/0xb0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
Memory state around the buggy address:
ffff888128b97e80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff888128b97f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888128b97f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
^
ffff888128b98000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff888128b98080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
----------------
Code disassembly (best guess), 2 bytes skipped:
0: 49 8b 0e mov (%r14),%rcx
3: 49 39 ce cmp %rcx,%r14
6: 75 1a jne 0x22
8: e9 ab 00 00 00 jmp 0xb8
d: 66 0f 1f 84 00 00 00 nopw 0x0(%rax,%rax,1)
14: 00 00
16: 48 8b 09 mov (%rcx),%rcx
19: 49 39 ce cmp %rcx,%r14
1c: 0f 84 22 02 00 00 je 0x244
22: 44 39 49 10 cmp %r9d,0x10(%rcx)
26: 75 ee jne 0x16
* 28: 44 3b 79 14 cmp 0x14(%rcx),%r15d <-- trapping instruction
2c: 75 e8 jne 0x16
2e: 31 c0 xor %eax,%eax
30: 66 66 2e 0f 1f 84 00 data16 cs nopw 0x0(%rax,%rax,1)
37: 00 00 00 00
3b: 66 data16
3c: 66 data16
3d: 2e cs