==================================================================
BUG: KASAN: use-after-free in mcp2221_raw_event+0x110d/0x1140 drivers/hid/hid-mcp2221.c:975
Read of size 1 at addr ffff888113933fff by task pr/ttyS0/15
CPU: 1 UID: 0 PID: 15 Comm: pr/ttyS0 Not tainted syzkaller #0 PREEMPT(lazy)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
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+0x13d/0x4b0 mm/kasan/report.c:482
kasan_report+0xdf/0x1c0 mm/kasan/report.c:595
mcp2221_raw_event+0x110d/0x1140 drivers/hid/hid-mcp2221.c:975
__hid_input_report.constprop.0+0x319/0x470 drivers/hid/hid-core.c:2175
hid_irq_in+0x55d/0x710 drivers/hid/usbhid/hid-core.c:287
__usb_hcd_giveback_urb+0x38e/0x610 drivers/usb/core/hcd.c:1657
usb_hcd_giveback_urb+0x3ca/0x4a0 drivers/usb/core/hcd.c:1741
dummy_timer+0xdaf/0x3820 drivers/usb/gadget/udc/dummy_hcd.c:2023
__run_hrtimer kernel/time/hrtimer.c:2074 [inline]
__hrtimer_run_queues+0x462/0x9c0 kernel/time/hrtimer.c:2131
hrtimer_run_softirq+0x1ca/0x360 kernel/time/hrtimer.c:2148
handle_softirqs+0x1d9/0x9b0 kernel/softirq.c:645
__do_softirq kernel/softirq.c:679 [inline]
invoke_softirq kernel/softirq.c:519 [inline]
__irq_exit_rcu+0x168/0x210 kernel/softirq.c:758
irq_exit_rcu+0x9/0x30 kernel/softirq.c:775
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0x8f/0xb0 arch/x86/kernel/apic/apic.c:1062
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:211 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:221
Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 b6 67 04 fa 48 89 df e8 3e be 04 fa f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 75 02 f7 f9 65 48 83 3d b4 fe 97 05 00 74 16 5b
RSP: 0018:ffffc900000ffcb8 EFLAGS: 00000246
RAX: 0000000000000002 RBX: ffffffff944968e0 RCX: 0000000000000000
RDX: 0000000000000001 RSI: ffffffff892df159 RDI: ffffffff87d2bd80
RBP: 0000000000000246 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 205d313332355420 R12: 1ffff9200001ff9a
R13: ffffffff89ebc480 R14: 0000000000000001 R15: 0000000000000001
nbcon_emit_one+0x15c/0x2b0 kernel/printk/nbcon.c:1165
nbcon_kthread_func+0x613/0x7d0 kernel/printk/nbcon.c:1271
kthread+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x69f/0xc90 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:0xffff888113933b40 pfn:0x113933
flags: 0x200000000000000(node=0|zone=2)
raw: 0200000000000000 dead000000000100 dead000000000122 0000000000000000
raw: ffff888113933b40 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 0xd2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5027, tgid 5027 (modprobe), ts 98275824238
set_page_owner include/linux/page_owner.h:33 [inline]
post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1871
prep_new_page mm/page_alloc.c:1879 [inline]
get_page_from_freelist+0xf4b/0x3440 mm/page_alloc.c:3943
__alloc_frozen_pages_noprof+0x2d7/0x2f70 mm/page_alloc.c:5436
alloc_slab_page mm/slub.c:3347 [inline]
allocate_slab mm/slub.c:3462 [inline]
new_slab+0xa9/0x6e0 mm/slub.c:3513
refill_objects+0xe3/0x410 mm/slub.c:7418
refill_sheaf mm/slub.c:2885 [inline]
__pcs_replace_empty_main+0x35e/0x650 mm/slub.c:4774
alloc_from_pcs mm/slub.c:4850 [inline]
slab_alloc_node mm/slub.c:4984 [inline]
kmem_cache_alloc_noprof+0x471/0x650 mm/slub.c:5010
vm_area_alloc+0x1f/0x160 mm/vma_init.c:36
do_brk_flags+0x3f9/0x1750 mm/vma.c:3042
__do_sys_brk+0x66f/0xa50 mm/mmap.c:196
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x119/0x710 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 14 tgid 14 ts 141408722012 stack trace:
reset_page_owner include/linux/page_owner.h:26 [inline]
__free_pages_prepare mm/page_alloc.c:1418 [inline]
__free_frozen_pages+0x714/0xfc0 mm/page_alloc.c:2962
rcu_do_batch kernel/rcu/tree.c:2650 [inline]
rcu_core+0x5f0/0x1260 kernel/rcu/tree.c:2919
handle_softirqs+0x1d9/0x9b0 kernel/softirq.c:645
run_ksoftirqd kernel/softirq.c:1099 [inline]
run_ksoftirqd+0x38/0x60 kernel/softirq.c:1091
smpboot_thread_fn+0x3d3/0xab0 kernel/smpboot.c:160
kthread+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x69f/0xc90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Memory state around the buggy address:
ffff888113933e80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff888113933f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888113933f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
^
ffff888113934000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff888113934080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
----------------
Code disassembly (best guess):
0: f5 cmc
1: 53 push %rbx
2: 48 8b 74 24 10 mov 0x10(%rsp),%rsi
7: 48 89 fb mov %rdi,%rbx
a: 48 83 c7 18 add $0x18,%rdi
e: e8 b6 67 04 fa call 0xfa0467c9
13: 48 89 df mov %rbx,%rdi
16: e8 3e be 04 fa call 0xfa04be59
1b: f7 c5 00 02 00 00 test $0x200,%ebp
21: 75 23 jne 0x46
23: 9c pushf
24: 58 pop %rax
25: f6 c4 02 test $0x2,%ah
28: 75 37 jne 0x61
* 2a: bf 01 00 00 00 mov $0x1,%edi <-- trapping instruction
2f: e8 75 02 f7 f9 call 0xf9f702a9
34: 65 48 83 3d b4 fe 97 cmpq $0x0,%gs:0x597feb4(%rip) # 0x597fef1
3b: 05 00
3d: 74 16 je 0x55
3f: 5b pop %rbx