==================================================================
BUG: KASAN: slab-out-of-bounds in mcp2221_raw_event+0x106a/0x1240 drivers/hid/hid-mcp2221.c:950
Read of size 1 at addr ffff88803c75ffff by task ktimers/0/16

CPU: 0 UID: 0 PID: 16 Comm: ktimers/0 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/27/2026
Call Trace:
 <TASK>
 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:2139 [inline]
 hid_input_report+0x420/0x580 drivers/hid/hid-core.c:2166
 hid_irq_in+0x47e/0x6d0 drivers/hid/usbhid/hid-core.c:286
 __usb_hcd_giveback_urb+0x3b3/0x5e0 drivers/usb/core/hcd.c:1657
 dummy_timer+0x8a6/0x4710 drivers/usb/gadget/udc/dummy_hcd.c:1995
 __run_hrtimer kernel/time/hrtimer.c:1785 [inline]
 __hrtimer_run_queues+0x55f/0xda0 kernel/time/hrtimer.c:1849
 hrtimer_run_softirq+0x192/0x5d0 kernel/time/hrtimer.c:1866
 handle_softirqs+0x1de/0x6f0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 run_ktimerd+0x69/0x100 kernel/softirq.c:1138
 smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160
 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
 </TASK>

Allocated by task 6165:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __do_kmalloc_node mm/slub.c:5263 [inline]
 __kmalloc_noprof+0x3e7/0x7b0 mm/slub.c:5275
 kmalloc_noprof include/linux/slab.h:954 [inline]
 kzalloc_noprof include/linux/slab.h:1188 [inline]
 __register_sysctl_table+0x72/0x1340 fs/proc/proc_sysctl.c:1379
 mpls_dev_sysctl_register+0x191/0x280 net/mpls/af_mpls.c:1437
 mpls_add_dev net/mpls/af_mpls.c:1490 [inline]
 mpls_dev_notify+0x394/0xd10 net/mpls/af_mpls.c:1635
 notifier_call_chain+0x1be/0x400 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2287 [inline]
 call_netdevice_notifiers net/core/dev.c:2301 [inline]
 register_netdevice+0x1751/0x1d10 net/core/dev.c:11462
 register_netdev+0x40/0x60 net/core/dev.c:11540
 vti6_init_net+0x238/0x370 net/ipv6/ip6_vti.c:1158
 ops_init+0x35c/0x5c0 net/core/net_namespace.c:137
 setup_net+0x118/0x340 net/core/net_namespace.c:446
 copy_net_ns+0x50e/0x730 net/core/net_namespace.c:581
 create_new_namespaces+0x3e7/0x6a0 kernel/nsproxy.c:130
 unshare_nsproxy_namespaces+0x11a/0x160 kernel/nsproxy.c:226
 ksys_unshare+0x51d/0x930 kernel/fork.c:3174
 __do_sys_unshare kernel/fork.c:3245 [inline]
 __se_sys_unshare kernel/fork.c:3243 [inline]
 __x64_sys_unshare+0x38/0x50 kernel/fork.c:3243
 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

Freed by task 1454:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2692 [inline]
 slab_free_freelist_hook mm/slub.c:2721 [inline]
 slab_free_bulk mm/slub.c:6205 [inline]
 kmem_cache_free_bulk+0x313/0x1220 mm/slub.c:7009
 kfree_bulk include/linux/slab.h:823 [inline]
 kvfree_rcu_bulk+0xe5/0x1b0 mm/slab_common.c:1502
 kfree_rcu_work+0xed/0x170 mm/slab_common.c:1580
 process_one_work kernel/workqueue.c:3275 [inline]
 process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358
 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
 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

Last potentially related work creation:
 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57
 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
 kvfree_call_rcu+0x90/0x3c0 mm/slab_common.c:1970
 drop_sysctl_table+0x404/0x5e0 fs/proc/proc_sysctl.c:1521
 unregister_sysctl_table+0x41/0x60 fs/proc/proc_sysctl.c:1542
 mpls_dev_sysctl_unregister+0x8b/0xc0 net/mpls/af_mpls.c:1461
 mpls_dev_notify+0xb2d/0xd10 net/mpls/af_mpls.c:1679
 notifier_call_chain+0x1be/0x400 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2287 [inline]
 call_netdevice_notifiers net/core/dev.c:2301 [inline]
 unregister_netdevice_many_notify+0x186a/0x2360 net/core/dev.c:12414
 ops_exit_rtnl_list net/core/net_namespace.c:187 [inline]
 ops_undo_list+0x3d3/0x940 net/core/net_namespace.c:248
 cleanup_net+0x56e/0x800 net/core/net_namespace.c:704
 process_one_work kernel/workqueue.c:3275 [inline]
 process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358
 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
 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

The buggy address belongs to the object at ffff88803c75ff00
 which belongs to the cache kmalloc-cg-128 of size 128
The buggy address is located 127 bytes to the right of
 allocated 128-byte region [ffff88803c75ff00, ffff88803c75ff80)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88803c75f600 pfn:0x3c75f
memcg:ffff88803c75f091
flags: 0x80000000000200(workingset|node=0|zone=1)
page_type: f5(slab)
raw: 0080000000000200 ffff88813fe2fdc0 ffffea0000c72510 ffffea00017ad410
raw: ffff88803c75f600 000001000010000f 00000000f5000000 ffff88803c75f091
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0xd2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5833, tgid 5833 (syz-executor), ts 83761841046, free_ts 83760501506
 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+0x28bb/0x2950 mm/page_alloc.c:3962
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250
 alloc_slab_page mm/slub.c:3296 [inline]
 allocate_slab+0x77/0x660 mm/slub.c:3485
 new_slab mm/slub.c:3543 [inline]
 refill_objects+0x334/0x3c0 mm/slub.c:7178
 __pcs_replace_empty_main+0x371/0x5c0 mm/slub.c:-1
 alloc_from_pcs mm/slub.c:4720 [inline]
 slab_alloc_node mm/slub.c:4854 [inline]
 __do_kmalloc_node mm/slub.c:5262 [inline]
 __kmalloc_noprof+0x530/0x7b0 mm/slub.c:5275
 kmalloc_noprof include/linux/slab.h:954 [inline]
 kzalloc_noprof include/linux/slab.h:1188 [inline]
 __register_sysctl_table+0x72/0x1340 fs/proc/proc_sysctl.c:1379
 mpls_dev_sysctl_register+0x191/0x280 net/mpls/af_mpls.c:1437
 mpls_add_dev net/mpls/af_mpls.c:1490 [inline]
 mpls_dev_notify+0x394/0xd10 net/mpls/af_mpls.c:1635
 notifier_call_chain+0x1be/0x400 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2287 [inline]
 call_netdevice_notifiers net/core/dev.c:2301 [inline]
 register_netdevice+0x1751/0x1d10 net/core/dev.c:11462
 __ip_tunnel_create+0x3e8/0x560 net/ipv4/ip_tunnel.c:268
 ip_tunnel_init_net+0x2e7/0x840 net/ipv4/ip_tunnel.c:1147
 vti_init_net+0x2f/0x100 net/ipv4/ip_vti.c:517
 ops_init+0x35c/0x5c0 net/core/net_namespace.c:137
page last free pid 5833 tgid 5833 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1433 [inline]
 __free_frozen_pages+0xfe3/0x1170 mm/page_alloc.c:2978
 __slab_free+0x24f/0x2a0 mm/slub.c:5576
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4542 [inline]
 slab_alloc_node mm/slub.c:4869 [inline]
 __kmalloc_cache_noprof+0x338/0x690 mm/slub.c:5378
 kmalloc_noprof include/linux/slab.h:950 [inline]
 kzalloc_noprof include/linux/slab.h:1188 [inline]
 ref_tracker_alloc+0x15e/0x4a0 lib/ref_tracker.c:270
 __netdev_tracker_alloc include/linux/netdevice.h:4435 [inline]
 netdev_hold include/linux/netdevice.h:4464 [inline]
 netdev_queue_add_kobject net/core/net-sysfs.c:1994 [inline]
 netdev_queue_update_kobjects+0x1ce/0x6b0 net/core/net-sysfs.c:2056
 register_queue_kobjects net/core/net-sysfs.c:2119 [inline]
 netdev_register_kobject+0x258/0x310 net/core/net-sysfs.c:2362
 register_netdevice+0x12d7/0x1d10 net/core/dev.c:11424
 __ip_tunnel_create+0x3e8/0x560 net/ipv4/ip_tunnel.c:268
 ip_tunnel_init_net+0x2e7/0x840 net/ipv4/ip_tunnel.c:1147
 vti_init_net+0x2f/0x100 net/ipv4/ip_vti.c:517
 ops_init+0x35c/0x5c0 net/core/net_namespace.c:137
 setup_net+0x118/0x340 net/core/net_namespace.c:446
 copy_net_ns+0x50e/0x730 net/core/net_namespace.c:581

Memory state around the buggy address:
 ffff88803c75fe80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88803c75ff00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88803c75ff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                                                ^
 ffff88803c760000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88803c760080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================