================================================================== BUG: KASAN: slab-use-after-free in kernfs_root+0x29a/0x2a0 fs/kernfs/kernfs-internal.h:77 Read of size 8 at addr ffff888076f5e7b0 by task kworker/0:1/11 CPU: 0 UID: 0 PID: 11 Comm: kworker/0:1 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Workqueue: events request_firmware_work_func 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 kernfs_root+0x29a/0x2a0 fs/kernfs/kernfs-internal.h:77 kernfs_add_one+0x57d/0xaa0 fs/kernfs/dir.c:867 kernfs_create_dir_ns+0x157/0x2b0 fs/kernfs/dir.c:1130 sysfs_create_dir_ns+0x13a/0x2b0 fs/sysfs/dir.c:59 create_dir lib/kobject.c:73 [inline] kobject_add_internal+0x2c8/0x930 lib/kobject.c:240 kobject_add_varg lib/kobject.c:374 [inline] kobject_add+0x16a/0x1e0 lib/kobject.c:426 class_dir_create_and_add drivers/base/core.c:3300 [inline] get_device_parent+0x382/0x4c0 drivers/base/core.c:3351 device_add+0x1ad/0x1970 drivers/base/core.c:3681 fw_load_sysfs_fallback drivers/base/firmware_loader/fallback.c:86 [inline] fw_load_from_user_helper drivers/base/firmware_loader/fallback.c:162 [inline] firmware_fallback_sysfs+0x2e2/0xc20 drivers/base/firmware_loader/fallback.c:238 _request_firmware+0xfd7/0x13c0 drivers/base/firmware_loader/main.c:898 request_firmware_work_func+0xee/0x440 drivers/base/firmware_loader/main.c:1162 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322 process_scheduled_works kernel/workqueue.c:3405 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 11: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4612 [inline] slab_alloc_node mm/slub.c:4945 [inline] kmem_cache_alloc_noprof+0x26b/0x6a0 mm/slub.c:4959 __kernfs_new_node+0xd2/0xa10 fs/kernfs/dir.c:665 kernfs_new_node fs/kernfs/dir.c:751 [inline] kernfs_create_dir_ns+0xa6/0x2b0 fs/kernfs/dir.c:1120 sysfs_create_dir_ns+0x13a/0x2b0 fs/sysfs/dir.c:59 create_dir lib/kobject.c:73 [inline] kobject_add_internal+0x2c8/0x930 lib/kobject.c:240 kobject_add_varg lib/kobject.c:374 [inline] kobject_add+0x16a/0x1e0 lib/kobject.c:426 class_dir_create_and_add drivers/base/core.c:3300 [inline] get_device_parent+0x382/0x4c0 drivers/base/core.c:3351 device_add+0x1ad/0x1970 drivers/base/core.c:3681 fw_load_sysfs_fallback drivers/base/firmware_loader/fallback.c:86 [inline] fw_load_from_user_helper drivers/base/firmware_loader/fallback.c:162 [inline] firmware_fallback_sysfs+0x2e2/0xc20 drivers/base/firmware_loader/fallback.c:238 _request_firmware+0xfd7/0x13c0 drivers/base/firmware_loader/main.c:898 request_firmware_work_func+0xee/0x440 drivers/base/firmware_loader/main.c:1162 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322 process_scheduled_works kernel/workqueue.c:3405 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 15: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2705 [inline] slab_free mm/slub.c:6405 [inline] kmem_cache_free+0x127/0x6b0 mm/slub.c:6532 rcu_do_batch kernel/rcu/tree.c:2645 [inline] rcu_core+0x5a2/0x10d0 kernel/rcu/tree.c:2897 handle_softirqs+0x1ea/0x9b0 kernel/softirq.c:622 run_ksoftirqd kernel/softirq.c:1076 [inline] run_ksoftirqd+0x38/0x60 kernel/softirq.c:1068 smpboot_thread_fn+0x3d3/0xaa0 kernel/smpboot.c:160 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 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+0x30/0x50 mm/kasan/common.c:57 kasan_record_aux_stack+0xa7/0xc0 mm/kasan/generic.c:556 __call_rcu_common.constprop.0+0xa5/0x9b0 kernel/rcu/tree.c:3159 kernfs_put.part.0+0x3a6/0xaa0 fs/kernfs/dir.c:618 kernfs_put fs/kernfs/dir.c:590 [inline] __kernfs_remove+0x601/0xb80 fs/kernfs/dir.c:1603 kernfs_remove fs/kernfs/dir.c:1624 [inline] kernfs_remove+0x4b/0x70 fs/kernfs/dir.c:1613 sysfs_remove_dir+0xc8/0x110 fs/sysfs/dir.c:101 __kobject_del+0xe2/0x220 lib/kobject.c:604 kobject_del lib/kobject.c:627 [inline] kobject_del+0x3f/0x60 lib/kobject.c:619 device_del+0x630/0x9b0 drivers/base/core.c:3981 usb_disconnect+0x5b5/0x9a0 drivers/usb/core/hub.c:2376 hub_port_connect drivers/usb/core/hub.c:5407 [inline] hub_port_connect_change drivers/usb/core/hub.c:5707 [inline] port_event drivers/usb/core/hub.c:5871 [inline] hub_event+0x1d0c/0x4af0 drivers/usb/core/hub.c:5953 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322 process_scheduled_works kernel/workqueue.c:3405 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 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 ffff888076f5e780 which belongs to the cache kernfs_node_cache of size 176 The buggy address is located 48 bytes inside of freed 176-byte region [ffff888076f5e780, ffff888076f5e830) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x76f5e flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88801d2db500 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800110011 00000000f5000000 0000000000000000 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 5605, tgid 5605 (syz-executor), ts 65957005650, free_ts 65950827147 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1859 prep_new_page mm/page_alloc.c:1867 [inline] get_page_from_freelist+0xf48/0x3530 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x299/0x2dc0 mm/page_alloc.c:5304 alloc_slab_page mm/slub.c:3294 [inline] allocate_slab mm/slub.c:3408 [inline] new_slab+0xa2/0x650 mm/slub.c:3454 refill_objects+0xe3/0x410 mm/slub.c:7338 refill_sheaf mm/slub.c:2832 [inline] __pcs_replace_empty_main+0x376/0x680 mm/slub.c:4703 alloc_from_pcs mm/slub.c:4801 [inline] slab_alloc_node mm/slub.c:4933 [inline] kmem_cache_alloc_noprof+0x46e/0x6a0 mm/slub.c:4959 __kernfs_new_node+0xd2/0xa10 fs/kernfs/dir.c:665 kernfs_new_node+0x117/0x150 fs/kernfs/dir.c:751 __kernfs_create_file+0x53/0x350 fs/kernfs/file.c:1050 sysfs_add_file_mode_ns+0x207/0x3c0 fs/sysfs/file.c:316 create_files fs/sysfs/group.c:82 [inline] internal_create_group+0x593/0xfb0 fs/sysfs/group.c:189 internal_create_groups+0x9d/0x150 fs/sysfs/group.c:229 device_add_groups drivers/base/core.c:2907 [inline] device_add_attrs drivers/base/core.c:2971 [inline] device_add+0x71a/0x1970 drivers/base/core.c:3711 netdev_register_kobject+0x1a9/0x3d0 net/core/net-sysfs.c:2337 register_netdevice+0x15b6/0x25a0 net/core/dev.c:11440 page last free pid 5606 tgid 5606 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1406 [inline] __free_frozen_pages+0x79f/0x1090 mm/page_alloc.c:2950 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x47/0xf0 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4612 [inline] slab_alloc_node mm/slub.c:4945 [inline] kmem_cache_alloc_node_noprof+0x27d/0x6b0 mm/slub.c:5017 kmalloc_reserve+0x148/0x350 net/core/skbuff.c:615 __alloc_skb+0x185/0x710 net/core/skbuff.c:715 alloc_skb include/linux/skbuff.h:1384 [inline] nlmsg_new include/net/netlink.h:1055 [inline] netlink_ack+0x117/0xb80 net/netlink/af_netlink.c:2493 netlink_rcv_skb+0x333/0x420 net/netlink/af_netlink.c:2562 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x585/0x850 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1900 sock_sendmsg_nosec net/socket.c:775 [inline] __sock_sendmsg net/socket.c:790 [inline] __sys_sendto+0x48b/0x4e0 net/socket.c:2252 __do_sys_sendto net/socket.c:2259 [inline] __se_sys_sendto net/socket.c:2255 [inline] __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2255 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888076f5e680: fc fc fa fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888076f5e700: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff888076f5e780: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888076f5e800: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fa fb ffff888076f5e880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================