==================================================================
BUG: KASAN: use-after-free in mcp2221_raw_event+0x103c/0x10a0 drivers/hid/hid-mcp2221.c:948
Read of size 1 at addr ffff88815ef03fff by task kworker/0:6/17478
CPU: 0 UID: 0 PID: 17478 Comm: kworker/0:6 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:write_comp_data+0x2b/0x90 kernel/kcov.c:272
Code: 8b 05 39 2b 1a 0b 49 89 f8 49 89 f1 49 89 d2 65 48 8b 3d 10 2b 1a 0b a9 00 01 ff 00 74 1b f6 c4 01 74 07 a9 00 00 ff 00 74 05 c0 34 a5 05 8b 87 64 15 00 00 85 c0 74 f1 8b 87 40 15 00 00 83
RSP: 0018:ffffc9000419e840 EFLAGS: 00000297
RAX: 0000000000000002 RBX: ffff88815c81df00 RCX: ffffffff8242eea6
RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff88813c471d40
RBP: ffff8881353bc5a0 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000001
R13: ffff8881353bc5a0 R14: ffff88815c81df00 R15: dffffc0000000000
kernfs_root+0x86/0x2a0 fs/kernfs/kernfs-internal.h:76
kernfs_link_sibling+0x518/0x770 fs/kernfs/dir.c:398
kernfs_add_one+0x1e7/0x850 fs/kernfs/dir.c:815
kernfs_create_link+0x1a9/0x240 fs/kernfs/symlink.c:48
sysfs_do_create_link_sd+0x90/0x140 fs/sysfs/symlink.c:44
sysfs_do_create_link fs/sysfs/symlink.c:80 [inline]
sysfs_create_link+0x61/0xc0 fs/sysfs/symlink.c:92
bus_add_device+0x16e/0x4a0 drivers/base/bus.c:544
device_add+0x9cf/0x1950 drivers/base/core.c:3646
i2c_register_adapter+0x39e/0x1240 drivers/i2c/i2c-core-base.c:1573
i2c_add_adapter drivers/i2c/i2c-core-base.c:1673 [inline]
i2c_add_adapter+0x10a/0x1a0 drivers/i2c/i2c-core-base.c:1653
devm_i2c_add_adapter+0x1b/0x90 drivers/i2c/i2c-core-base.c:1845
mcp2221_probe.cold+0x5de/0xab3 drivers/hid/hid-mcp2221.c:1289
__hid_device_probe drivers/hid/hid-core.c:2775 [inline]
hid_device_probe+0x50e/0x800 drivers/hid/hid-core.c:2812
call_driver_probe drivers/base/dd.c:581 [inline]
really_probe+0x241/0xa60 drivers/base/dd.c:659
__driver_probe_device+0x1de/0x400 drivers/base/dd.c:801
driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:831
__device_attach_driver+0x1df/0x340 drivers/base/dd.c:959
bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
__device_attach+0x1e4/0x4d0 drivers/base/dd.c:1031
device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1086
bus_probe_device+0x64/0x160 drivers/base/bus.c:574
device_add+0x11d9/0x1950 drivers/base/core.c:3689
hid_add_device+0x2bf/0x440 drivers/hid/hid-core.c:2951
usbhid_probe+0xd57/0x1350 drivers/hid/usbhid/hid-core.c:1450
usb_probe_interface+0x303/0x8f0 drivers/usb/core/driver.c:396
call_driver_probe drivers/base/dd.c:581 [inline]
really_probe+0x241/0xa60 drivers/base/dd.c:659
__driver_probe_device+0x1de/0x400 drivers/base/dd.c:801
driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:831
__device_attach_driver+0x1df/0x340 drivers/base/dd.c:959
bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
__device_attach+0x1e4/0x4d0 drivers/base/dd.c:1031
device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1086
bus_probe_device+0x64/0x160 drivers/base/bus.c:574
device_add+0x11d9/0x1950 drivers/base/core.c:3689
usb_set_configuration+0xd97/0x1c60 drivers/usb/core/message.c:2210
usb_generic_driver_probe+0xa1/0xe0 drivers/usb/core/generic.c:250
usb_probe_device+0xef/0x400 drivers/usb/core/driver.c:291
call_driver_probe drivers/base/dd.c:581 [inline]
really_probe+0x241/0xa60 drivers/base/dd.c:659
__driver_probe_device+0x1de/0x400 drivers/base/dd.c:801
driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:831
__device_attach_driver+0x1df/0x340 drivers/base/dd.c:959
bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
__device_attach+0x1e4/0x4d0 drivers/base/dd.c:1031
device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1086
bus_probe_device+0x64/0x160 drivers/base/bus.c:574
device_add+0x11d9/0x1950 drivers/base/core.c:3689
usb_new_device.cold+0x685/0x115c drivers/usb/core/hub.c:2695
hub_port_connect drivers/usb/core/hub.c:5567 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
port_event drivers/usb/core/hub.c:5871 [inline]
hub_event+0x314d/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:0x0 pfn:0x15ef03
flags: 0x200000000000000(node=0|zone=2)
raw: 0200000000000000 ffffea0004510948 ffffea0004510988 0000000000000000
raw: 0000000000000000 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 8680, tgid 8680 (udevd), ts 2776048476126, free_ts 2776260698084
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]
__pud_alloc_one_noprof include/asm-generic/pgalloc.h:181 [inline]
pud_alloc_one_noprof include/asm-generic/pgalloc.h:206 [inline]
__pud_alloc+0x3b/0x760 mm/memory.c:6642
pud_alloc include/linux/mm.h:3100 [inline]
copy_pud_range mm/memory.c:1409 [inline]
copy_p4d_range mm/memory.c:1453 [inline]
copy_page_range+0x20c6/0x25e0 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 8382 tgid 8382 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:
ffff88815ef03e80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff88815ef03f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88815ef03f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
^
ffff88815ef04000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff88815ef04080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
----------------
Code disassembly (best guess):
0: 8b 05 39 2b 1a 0b mov 0xb1a2b39(%rip),%eax # 0xb1a2b3f
6: 49 89 f8 mov %rdi,%r8
9: 49 89 f1 mov %rsi,%r9
c: 49 89 d2 mov %rdx,%r10
f: 65 48 8b 3d 10 2b 1a mov %gs:0xb1a2b10(%rip),%rdi # 0xb1a2b27
16: 0b
17: a9 00 01 ff 00 test $0xff0100,%eax
1c: 74 1b je 0x39
1e: f6 c4 01 test $0x1,%ah
21: 74 07 je 0x2a
23: a9 00 00 ff 00 test $0xff0000,%eax
28: 74 05 je 0x2f
* 2a: e9 c0 34 a5 05 jmp 0x5a534ef <-- trapping instruction
2f: 8b 87 64 15 00 00 mov 0x1564(%rdi),%eax
35: 85 c0 test %eax,%eax
37: 74 f1 je 0x2a
39: 8b 87 40 15 00 00 mov 0x1540(%rdi),%eax
3f: 83 .byte 0x83