usb 4-1: SerialNumber: syz
usb 4-1: config 0 descriptor??
em28xx 4-1:0.244: New device syz syz @ 480 Mbps (2040:026d, interface 244, class 244)
em28xx 4-1:0.244: Audio interface 244 found (Vendor Class)
em28xx 4-1:0.244: unknown em28xx chip ID (0)
em28xx 4-1:0.244: Config register raw data: 0xfffffffb
em28xx 4-1:0.244: AC97 chip type couldn't be determined
em28xx 4-1:0.244: No AC97 audio processor
==================================================================
BUG: KASAN: use-after-free in __list_add_valid_or_report+0xe4/0x100 lib/list_debug.c:32
Read of size 8 at addr ffff888111648250 by task kworker/0:2/1117

CPU: 0 UID: 0 PID: 1117 Comm: kworker/0:2 Not tainted 6.13.0-rc7-syzkaller-g26a6cc10f19a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: usb_hub_wq hub_event
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xc3/0x620 mm/kasan/report.c:489
 kasan_report+0xd9/0x110 mm/kasan/report.c:602
 __list_add_valid_or_report+0xe4/0x100 lib/list_debug.c:32
 __list_add_valid include/linux/list.h:88 [inline]
 __list_add include/linux/list.h:150 [inline]
 list_add_tail include/linux/list.h:183 [inline]
 em28xx_init_extension+0x48/0x200 drivers/media/usb/em28xx/em28xx-core.c:1114
 em28xx_init_dev.constprop.0+0x197b/0x3090 drivers/media/usb/em28xx/em28xx-cards.c:3679
 em28xx_usb_probe+0x1262/0x3720 drivers/media/usb/em28xx/em28xx-cards.c:4034
 usb_probe_interface+0x300/0x9c0 drivers/usb/core/driver.c:396
 call_driver_probe drivers/base/dd.c:579 [inline]
 really_probe+0x23e/0xa90 drivers/base/dd.c:658
 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:800
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:830
 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:958
 bus_for_each_drv+0x157/0x1e0 drivers/base/bus.c:459
 __device_attach+0x1e8/0x4b0 drivers/base/dd.c:1030
 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:534
 device_add+0x114b/0x1a70 drivers/base/core.c:3665
 usb_set_configuration+0x10cb/0x1c50 drivers/usb/core/message.c:2210
 usb_generic_driver_probe+0xb1/0x110 drivers/usb/core/generic.c:254
 usb_probe_device+0xec/0x3e0 drivers/usb/core/driver.c:291
 call_driver_probe drivers/base/dd.c:579 [inline]
 really_probe+0x23e/0xa90 drivers/base/dd.c:658
 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:800
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:830
 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:958
 bus_for_each_drv+0x157/0x1e0 drivers/base/bus.c:459
 __device_attach+0x1e8/0x4b0 drivers/base/dd.c:1030
 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:534
 device_add+0x114b/0x1a70 drivers/base/core.c:3665
 usb_new_device+0xd09/0x1a20 drivers/usb/core/hub.c:2651
 hub_port_connect drivers/usb/core/hub.c:5523 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5663 [inline]
 port_event drivers/usb/core/hub.c:5823 [inline]
 hub_event+0x2e58/0x4f40 drivers/usb/core/hub.c:5905
 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3236
 process_scheduled_works kernel/workqueue.c:3317 [inline]
 worker_thread+0x6c8/0xf00 kernel/workqueue.c:3398
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888111649e00 pfn:0x111648
flags: 0x200000000000000(node=0|zone=2)
raw: 0200000000000000 ffffea00043bd508 ffffea00044b0208 0000000000000000
raw: ffff888111649e00 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 0x92000(__GFP_NOWARN|__GFP_NORETRY|__GFP_NOMEMALLOC), pid 1117, tgid 1117 (kworker/0:2), ts 79169342431, free_ts 79169387246
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1558
 prep_new_page mm/page_alloc.c:1566 [inline]
 get_page_from_freelist+0xe76/0x2b90 mm/page_alloc.c:3476
 __alloc_pages_noprof+0x21c/0x22a0 mm/page_alloc.c:4753
 alloc_pages_mpol_noprof+0xeb/0x400 mm/mempolicy.c:2269
 stack_depot_save_flags+0x8aa/0x9c0 lib/stackdepot.c:627
 kasan_save_stack+0x42/0x60 mm/kasan/common.c:48
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:582
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x37/0x50 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2353 [inline]
 slab_free mm/slub.c:4613 [inline]
 kfree+0x130/0x470 mm/slub.c:4761
 em28xx_free_device drivers/media/usb/em28xx/em28xx-cards.c:3564 [inline]
 kref_put include/linux/kref.h:65 [inline]
 em28xx_usb_disconnect+0x3ec/0x610 drivers/media/usb/em28xx/em28xx-cards.c:4207
 usb_unbind_interface+0x1e2/0x960 drivers/usb/core/driver.c:458
 device_remove drivers/base/dd.c:569 [inline]
 device_remove+0x122/0x170 drivers/base/dd.c:561
 __device_release_driver drivers/base/dd.c:1273 [inline]
 device_release_driver_internal+0x44a/0x610 drivers/base/dd.c:1296
 bus_remove_device+0x22f/0x420 drivers/base/bus.c:576
 device_del+0x396/0x9f0 drivers/base/core.c:3854
page last free pid 1117 tgid 1117 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1127 [inline]
 free_unref_page+0x661/0xe40 mm/page_alloc.c:2659
 stack_depot_save_flags+0x30e/0x9c0 lib/stackdepot.c:674
 kasan_save_stack+0x42/0x60 mm/kasan/common.c:48
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:582
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x37/0x50 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2353 [inline]
 slab_free mm/slub.c:4613 [inline]
 kfree+0x130/0x470 mm/slub.c:4761
 em28xx_free_device drivers/media/usb/em28xx/em28xx-cards.c:3564 [inline]
 kref_put include/linux/kref.h:65 [inline]
 em28xx_usb_disconnect+0x3ec/0x610 drivers/media/usb/em28xx/em28xx-cards.c:4207
 usb_unbind_interface+0x1e2/0x960 drivers/usb/core/driver.c:458
 device_remove drivers/base/dd.c:569 [inline]
 device_remove+0x122/0x170 drivers/base/dd.c:561
 __device_release_driver drivers/base/dd.c:1273 [inline]
 device_release_driver_internal+0x44a/0x610 drivers/base/dd.c:1296
 bus_remove_device+0x22f/0x420 drivers/base/bus.c:576
 device_del+0x396/0x9f0 drivers/base/core.c:3854
 usb_disable_device+0x36c/0x7f0 drivers/usb/core/message.c:1418
 usb_disconnect+0x2e1/0x920 drivers/usb/core/hub.c:2304
 hub_port_connect drivers/usb/core/hub.c:5363 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5663 [inline]
 port_event drivers/usb/core/hub.c:5823 [inline]
 hub_event+0x1bed/0x4f40 drivers/usb/core/hub.c:5905

Memory state around the buggy address:
 ffff888111648100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888111648180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888111648200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                 ^
 ffff888111648280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888111648300: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================