==================================================================
BUG: KASAN: use-after-free in mcp2221_raw_event+0x106a/0x1240 drivers/hid/hid-mcp2221.c:950
Read of size 1 at addr ffff88805d203fff by task syz.4.3441/18944
CPU: 0 UID: 0 PID: 18944 Comm: syz.4.3441 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xba/0x230 mm/kasan/report.c:482
kasan_report+0x117/0x150 mm/kasan/report.c:595
mcp2221_raw_event+0x106a/0x1240 drivers/hid/hid-mcp2221.c:950
__hid_input_report drivers/hid/hid-core.c:2140 [inline]
hid_input_report+0x41d/0x580 drivers/hid/hid-core.c:2167
hid_irq_in+0x47e/0x6d0 drivers/hid/usbhid/hid-core.c:286
__usb_hcd_giveback_urb+0x376/0x540 drivers/usb/core/hcd.c:1657
dummy_timer+0xbbd/0x45d0 drivers/usb/gadget/udc/dummy_hcd.c:1995
__run_hrtimer kernel/time/hrtimer.c:1785 [inline]
__hrtimer_run_queues+0x53a/0xcc0 kernel/time/hrtimer.c:1849
hrtimer_run_softirq+0x182/0x5a0 kernel/time/hrtimer.c:1866
handle_softirqs+0x22a/0x870 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0x5f/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+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
RIP: 0010:rcu_is_watching+0x10/0xb0 kernel/rcu/tree.c:752
Code: 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 41 56 53 65 ff 05 a0 9e 71 11 0b 6b 04 0a 89 c3 83 f8 08 73 65 49 bf 00 00 00 00 00 fc ff df
RSP: 0018:ffffc90007007238 EFLAGS: 00000282
RAX: 0000000000000001 RBX: ffffffff90a54301 RCX: ffff8880326f3d00
RDX: ffffc90007007301 RSI: dffffc0000000000 RDI: ffffc90007007390
RBP: dffffc0000000000 R08: ffffc90007007410 R09: 0000000000000000
R10: ffffc900070073d8 R11: fffff52000e00e7d R12: ffffc90007007420
R13: ffffc90007000000 R14: ffffc90007007388 R15: ffffffff81767e95
rcu_read_unlock include/linux/rcupdate.h:879 [inline]
class_rcu_destructor include/linux/rcupdate.h:1193 [inline]
unwind_next_frame+0x1a66/0x23c0 arch/x86/kernel/unwind_orc.c:695
__unwind_start+0x5b8/0x760 arch/x86/kernel/unwind_orc.c:773
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0xe3/0x150 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57
kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
__call_rcu_common kernel/rcu/tree.c:3131 [inline]
call_rcu+0xee/0x890 kernel/rcu/tree.c:3251
destroy_inode fs/inode.c:402 [inline]
evict+0x95b/0xb10 fs/inode.c:870
__dentry_kill+0x1a2/0x5e0 fs/dcache.c:670
finish_dput+0xc9/0x480 fs/dcache.c:879
find_next_child+0x1e5/0x250 fs/libfs.c:594
__simple_recursive_removal+0x10b/0x520 fs/libfs.c:611
simple_recursive_removal fs/libfs.c:648 [inline]
simple_remove_by_name+0xb8/0x100 fs/libfs.c:659
fuse_ctl_remove_conn+0x15c/0x220 fs/fuse/control.c:305
fuse_conn_destroy+0x2fe/0x3b0 fs/fuse/inode.c:2098
fuse_sb_destroy fs/fuse/inode.c:2112 [inline]
fuse_kill_sb_anon+0x1ef/0x270 fs/fuse/inode.c:2125
deactivate_locked_super+0xbc/0x130 fs/super.c:476
cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312
task_work_run+0x1d9/0x270 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff4c1b9da0a
Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff4c2990e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffec RBX: 00007ff4c2990ee0 RCX: 00007ff4c1b9da0a
RDX: 0000200000000200 RSI: 0000200000000240 RDI: 0000000000000000
RBP: 0000200000000200 R08: 00007ff4c2990ee0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000240
R13: 00007ff4c2990ea0 R14: 0000000000000000 R15: 0000200000000280
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88805d203000 pfn:0x5d203
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea0001748088 ffffea000109d888 0000000000000000
raw: ffff88805d203000 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 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 18600, tgid 18597 (syz.4.3349), ts 1053517058243, free_ts 1077407307548
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x231/0x280 mm/page_alloc.c:1889
prep_new_page mm/page_alloc.c:1897 [inline]
get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3962
__alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250
alloc_slab_page mm/slub.c:3292 [inline]
allocate_slab+0x77/0x660 mm/slub.c:3481
new_slab mm/slub.c:3539 [inline]
refill_objects+0x331/0x3c0 mm/slub.c:7175
__kmem_cache_alloc_bulk+0x3c/0x1a0 mm/slub.c:7212
kmem_cache_alloc_bulk_noprof+0x4d3/0x7e0 mm/slub.c:7264
__io_alloc_req_refill+0xb4/0x360 io_uring/io_uring.c:965
io_alloc_req io_uring/io_uring.h:508 [inline]
io_submit_sqes+0x1011/0x2400 io_uring/io_uring.c:2032
__do_sys_io_uring_enter io_uring/io_uring.c:2604 [inline]
__se_sys_io_uring_enter+0x2cc/0x18c0 io_uring/io_uring.c:2539
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 11283 tgid 11283 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1433 [inline]
__free_frozen_pages+0xc2b/0xdb0 mm/page_alloc.c:2978
rcu_do_batch kernel/rcu/tree.c:2617 [inline]
rcu_core+0x7cd/0x1070 kernel/rcu/tree.c:2869
handle_softirqs+0x22a/0x870 kernel/softirq.c:622
do_softirq+0x76/0xd0 kernel/softirq.c:523
__local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450
local_bh_enable include/linux/bottom_half.h:33 [inline]
__alloc_skb+0x1aa/0x7d0 net/core/skbuff.c:697
alloc_skb include/linux/skbuff.h:1383 [inline]
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:819 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:876 [inline]
nsim_dev_trap_report_work+0x29a/0xb80 drivers/net/netdevsim/dev.c:922
process_one_work kernel/workqueue.c:3276 [inline]
process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 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:
ffff88805d203e80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff88805d203f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88805d203f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
^
ffff88805d204000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff88805d204080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
----------------
Code disassembly (best guess):
0: 66 2e 0f 1f 84 00 00 cs nopw 0x0(%rax,%rax,1)
7: 00 00 00
a: 90 nop
b: 90 nop
c: 90 nop
d: 90 nop
e: 90 nop
f: 90 nop
10: 90 nop
11: 90 nop
12: 90 nop
13: 90 nop
14: 90 nop
15: 90 nop
16: 90 nop
17: 90 nop
18: 90 nop
19: 90 nop
1a: f3 0f 1e fa endbr64
1e: 41 57 push %r15
20: 41 56 push %r14
22: 53 push %rbx
23: 65 ff 05 a0 9e 71 11 incl %gs:0x11719ea0(%rip) # 0x11719eca
* 2a: e8 0b 6b 04 0a call 0xa046b3a <-- trapping instruction
2f: 89 c3 mov %eax,%ebx
31: 83 f8 08 cmp $0x8,%eax
34: 73 65 jae 0x9b
36: 49 bf 00 00 00 00 00 movabs $0xdffffc0000000000,%r15
3d: fc ff df