==================================================================
BUG: KASAN: use-after-free in mcp2221_raw_event+0x103c/0x10a0 drivers/hid/hid-mcp2221.c:948
Read of size 1 at addr ffff888142e63fff by task kworker/0:2/5212
CPU: 0 UID: 0 PID: 5212 Comm: kworker/0:2 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
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/0x1e0 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:1785 [inline]
__hrtimer_run_queues+0x50e/0xa70 kernel/time/hrtimer.c:1849
hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1866
handle_softirqs+0x1de/0x9d0 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:3270
Code: 00 e8 51 5d 28 00 9c 5d 81 e5 00 02 00 00 31 ff 48 89 ee e8 7f 65 20 00 48 85 ed 0f 85 d7 01 00 00 e8 91 6a 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:ffffc9000322f830 EFLAGS: 00000293
RAX: ffffffff89c75f58 RBX: ffffffff89c75f00 RCX: ffffffff81914f61
RDX: ffff888118d03a00 RSI: ffffffff81914f6f RDI: ffff888118d03a00
RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 000000000002f548
R13: ffffffff89c75f58 R14: ffffc9000322f8b0 R15: dffffc0000000000
console_flush_all kernel/printk/printk.c:3343 [inline]
__console_flush_and_unlock kernel/printk/printk.c:3373 [inline]
console_unlock+0x103/0x260 kernel/printk/printk.c:3413
vprintk_emit+0x407/0x6b0 kernel/printk/printk.c:2479
_printk+0xcf/0x110 kernel/printk/printk.c:2504
legacy_dvb_usb_read_remote_control.cold+0x11/0x16 drivers/media/usb/dvb-usb/dvb-usb-remote.c:124
process_one_work+0x9d7/0x1920 kernel/workqueue.c:3275
process_scheduled_works kernel/workqueue.c:3358 [inline]
worker_thread+0x5da/0xe40 kernel/workqueue.c:3439
kthread+0x370/0x450 kernel/kthread.c:467
ret_from_fork+0x6c3/0xcb0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888100000000 pfn:0x142e63
flags: 0x200000000000000(node=0|zone=2)
raw: 0200000000000000 dead000000000100 dead000000000122 0000000000000000
raw: ffff888100000000 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 2968, tgid 2968 (syz-executor), ts 1703671099649, free_ts 1706853718778
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x153/0x170 mm/page_alloc.c:1889
prep_new_page mm/page_alloc.c:1897 [inline]
get_page_from_freelist+0xf10/0x39f0 mm/page_alloc.c:3962
__alloc_frozen_pages_noprof+0x273/0x2860 mm/page_alloc.c:5250
alloc_pages_mpol+0xe8/0x410 mm/mempolicy.c:2484
alloc_frozen_pages_noprof mm/mempolicy.c:2555 [inline]
alloc_pages_noprof+0x131/0x390 mm/mempolicy.c:2575
pagetable_alloc_noprof include/linux/mm.h:3404 [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:466
copy_pte_range mm/memory.c:1250 [inline]
copy_pmd_range mm/memory.c:1405 [inline]
copy_pud_range mm/memory.c:1442 [inline]
copy_p4d_range mm/memory.c:1466 [inline]
copy_page_range+0x1643/0x2630 mm/memory.c:1552
dup_mmap+0xcb9/0x1f30 mm/mmap.c:1841
dup_mm kernel/fork.c:1530 [inline]
copy_mm kernel/fork.c:1582 [inline]
copy_process+0x459f/0x7800 kernel/fork.c:2223
kernel_clone+0xfc/0x9a0 kernel/fork.c:2654
__do_sys_clone+0xd9/0x120 kernel/fork.c:2795
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x106/0x7b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 15050 tgid 15050 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1433 [inline]
__free_frozen_pages+0x7b1/0xfb0 mm/page_alloc.c:2978
__pagetable_free include/linux/mm.h:3414 [inline]
pagetable_free include/linux/mm.h:3438 [inline]
pagetable_dtor_free include/linux/mm.h:3542 [inline]
__tlb_remove_table include/asm-generic/tlb.h:221 [inline]
__tlb_remove_table_free mm/mmu_gather.c:228 [inline]
tlb_remove_table_rcu+0x2b2/0x390 mm/mmu_gather.c:291
rcu_do_batch kernel/rcu/tree.c:2617 [inline]
rcu_core+0x5a2/0x10d0 kernel/rcu/tree.c:2869
handle_softirqs+0x1de/0x9d0 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:
ffff888142e63e80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff888142e63f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888142e63f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
^
ffff888142e64000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff888142e64080: 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: 51 push %rcx
3: 5d pop %rbp
4: 28 00 sub %al,(%rax)
6: 9c pushf
7: 5d pop %rbp
8: 81 e5 00 02 00 00 and $0x200,%ebp
e: 31 ff xor %edi,%edi
10: 48 89 ee mov %rbp,%rsi
13: e8 7f 65 20 00 call 0x206597
18: 48 85 ed test %rbp,%rbp
1b: 0f 85 d7 01 00 00 jne 0x1f8
21: e8 91 6a 20 00 call 0x206ab7
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