==================================================================
BUG: KASAN: use-after-free in mcp2221_raw_event+0x103c/0x10a0 drivers/hid/hid-mcp2221.c:948
Read of size 1 at addr ffff88812bc3bfff by task kworker/1:1/43
CPU: 1 UID: 0 PID: 43 Comm: kworker/1:1 Not tainted syzkaller #0 PREEMPT(voluntary)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Workqueue: events legacy_dvb_usb_read_remote_control
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:console_flush_one_record+0xac3/0xe50 kernel/printk/printk.c:3216
Code: 00 e8 11 59 28 00 9c 5d 81 e5 00 02 00 00 31 ff 48 89 ee e8 5f 76 20 00 48 85 ed 0f 85 d7 01 00 00 e8 71 7b 20 00 fb 4c 89 e8 <48> c1 e8 03 42 80 3c 38 00 0f 85 64 03 00 00 48 8b 0c 24 48 8b 6b
RSP: 0018:ffffc900004e7778 EFLAGS: 00000293
RAX: ffffffff89a50638 RBX: ffffffff89a505e0 RCX: ffffffff8190c081
RDX: ffff8881072e8000 RSI: ffffffff8190c08f RDI: ffff8881072e8000
RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000038477
R13: ffffffff89a50638 R14: ffffc900004e77f8 R15: dffffc0000000000
console_flush_all kernel/printk/printk.c:3289 [inline]
__console_flush_and_unlock kernel/printk/printk.c:3319 [inline]
console_unlock+0x103/0x260 kernel/printk/printk.c:3359
vprintk_emit+0x407/0x6b0 kernel/printk/printk.c:2426
_printk+0xcf/0x110 kernel/printk/printk.c:2451
m920x_read drivers/media/usb/dvb-usb/m920x.c:40 [inline]
m920x_rc_query.cold+0x2b/0x30 drivers/media/usb/dvb-usb/m920x.c:188
legacy_dvb_usb_read_remote_control+0x10c/0x4f0 drivers/media/usb/dvb-usb/dvb-usb-remote.c:123
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:0x12bc3b
flags: 0x200000000000000(node=0|zone=2)
raw: 0200000000000000 dead000000000100 dead000000000122 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 19437, tgid 19437 (syz.8.3276), ts 2018382963198, free_ts 2020211444331
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
do_fault_around mm/memory.c:5707 [inline]
do_read_fault mm/memory.c:5746 [inline]
do_fault mm/memory.c:5889 [inline]
do_pte_missing mm/memory.c:4401 [inline]
handle_pte_fault mm/memory.c:6273 [inline]
__handle_mm_fault+0x1dbd/0x2d30 mm/memory.c:6411
handle_mm_fault+0x36d/0xa20 mm/memory.c:6580
do_user_addr_fault+0x5ae/0x11d0 arch/x86/mm/fault.c:1336
handle_page_fault arch/x86/mm/fault.c:1476 [inline]
exc_page_fault+0x66/0xc0 arch/x86/mm/fault.c:1532
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
page last free pid 15267 tgid 15267 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:
ffff88812bc3be80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff88812bc3bf00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88812bc3bf80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
^
ffff88812bc3c000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff88812bc3c080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
----------------
Code disassembly (best guess):
0: 00 e8 add %ch,%al
2: 11 59 28 adc %ebx,0x28(%rcx)
5: 00 9c 5d 81 e5 00 02 add %bl,0x200e581(%rbp,%rbx,2)
c: 00 00 add %al,(%rax)
e: 31 ff xor %edi,%edi
10: 48 89 ee mov %rbp,%rsi
13: e8 5f 76 20 00 call 0x207677
18: 48 85 ed test %rbp,%rbp
1b: 0f 85 d7 01 00 00 jne 0x1f8
21: e8 71 7b 20 00 call 0x207b97
26: fb sti
27: 4c 89 e8 mov %r13,%rax
* 2a: 48 c1 e8 03 shr $0x3,%rax <-- trapping instruction
2e: 42 80 3c 38 00 cmpb $0x0,(%rax,%r15,1)
33: 0f 85 64 03 00 00 jne 0x39d
39: 48 8b 0c 24 mov (%rsp),%rcx
3d: 48 rex.W
3e: 8b .byte 0x8b
3f: 6b .byte 0x6b