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BUG: KASAN: use-after-free in __list_add_valid_or_report+0x112/0x130 lib/list_debug.c:32
Read of size 8 at addr ffff88811a7dc250 by task kworker/1:0/23

CPU: 1 UID: 0 PID: 23 Comm: kworker/1:0 Not tainted syzkaller #0 PREEMPT(lazy) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: events request_module_async
Call Trace:
 <TASK>
 __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
 __list_add_valid_or_report+0x112/0x130 lib/list_debug.c:32
 __list_add_valid include/linux/list.h:96 [inline]
 __list_add include/linux/list.h:158 [inline]
 list_add_tail include/linux/list.h:191 [inline]
 em28xx_init_extension+0x48/0x200 drivers/media/usb/em28xx/em28xx-core.c:1245
 request_module_async+0x61/0x80 drivers/media/usb/em28xx/em28xx-cards.c:3660
 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+0x69a/0xc80 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88811a7ddc00 pfn:0x11a7dc
flags: 0x200000000000000(node=0|zone=2)
raw: 0200000000000000 ffffea00044e5108 ffff8881f573f2c0 0000000000000000
raw: ffff88811a7ddc00 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 2, migratetype Unmovable, gfp_mask 0x40cc0(GFP_KERNEL|__GFP_COMP), pid 28, tgid 28 (kworker/1:1), ts 315930165683, free_ts 316139434692
 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+0xf25/0x3400 mm/page_alloc.c:3946
 __alloc_frozen_pages_noprof+0x28f/0x2b90 mm/page_alloc.c:5304
 alloc_pages_mpol+0xe8/0x410 mm/mempolicy.c:2490
 ___kmalloc_large_node+0xe5/0x120 mm/slub.c:5302
 __kmalloc_large_noprof+0x1c/0x70 mm/slub.c:5323
 _kmalloc_noprof include/linux/slab.h:966 [inline]
 rtl92cu_init_sw_vars+0x121/0x190 drivers/net/wireless/realtek/rtlwifi/rtl8192cu/sw.c:43
 rtl_usb_probe.cold+0x79c/0xc1a drivers/net/wireless/realtek/rtlwifi/usb.c:1016
 usb_probe_interface+0x303/0x8f0 drivers/usb/core/driver.c:396
 call_driver_probe drivers/base/dd.c:628 [inline]
 really_probe+0x241/0xa60 drivers/base/dd.c:706
 __driver_probe_device+0x20e/0x450 drivers/base/dd.c:868
 driver_probe_device+0x4a/0x140 drivers/base/dd.c:898
 __device_attach_driver+0x1df/0x320 drivers/base/dd.c:1026
 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1098
 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1153
page last free pid 28 tgid 28 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1406 [inline]
 __free_frozen_pages+0x716/0xf50 mm/page_alloc.c:2950
 rtl92cu_deinit_sw_vars+0x66/0xc0 drivers/net/wireless/realtek/rtlwifi/rtl8192cu/sw.c:73
 rtl_usb_disconnect+0x22b/0x370 drivers/net/wireless/realtek/rtlwifi/usb.c:1070
 usb_unbind_interface+0x1dd/0x9e0 drivers/usb/core/driver.c:458
 device_remove drivers/base/dd.c:618 [inline]
 device_remove+0x12a/0x180 drivers/base/dd.c:610
 __device_release_driver drivers/base/dd.c:1349 [inline]
 device_release_driver_internal+0x44e/0x620 drivers/base/dd.c:1372
 bus_remove_device+0x2bc/0x560 drivers/base/bus.c:664
 device_del+0x376/0x9b0 drivers/base/core.c:3961
 usb_disable_device+0x367/0x810 drivers/usb/core/message.c:1478
 usb_disconnect+0x2e2/0x9a0 drivers/usb/core/hub.c:2345
 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+0x69a/0xc80 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:
 ffff88811a7dc100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88811a7dc180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88811a7dc200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                 ^
 ffff88811a7dc280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88811a7dc300: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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