syzbot

em28xx 1-1:0.132: Closing input extension
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BUG: KASAN: slab-use-after-free in media_device_unregister+0x154/0x470 drivers/media/mc/mc-device.c:-1
Read of size 8 at addr ffff8880338f8210 by task kworker/0:9/18273

CPU: 0 UID: 0 PID: 18273 Comm: kworker/0:9 Not tainted 6.15.0-rc3-syzkaller-00019-gbc3372351d0c #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: usb_hub_wq hub_event
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0x16e/0x5b0 mm/kasan/report.c:521
 kasan_report+0x143/0x180 mm/kasan/report.c:634
 media_device_unregister+0x154/0x470 drivers/media/mc/mc-device.c:-1
 em28xx_unregister_media_device drivers/media/usb/em28xx/em28xx-cards.c:3511 [inline]
 em28xx_release_resources+0xa7/0x230 drivers/media/usb/em28xx/em28xx-cards.c:3532
 em28xx_usb_disconnect+0x1cc/0x530 drivers/media/usb/em28xx/em28xx-cards.c:4201
 usb_unbind_interface+0x25b/0x940 drivers/usb/core/driver.c:458
 device_remove drivers/base/dd.c:569 [inline]
 __device_release_driver drivers/base/dd.c:1273 [inline]
 device_release_driver_internal+0x503/0x7c0 drivers/base/dd.c:1296
 bus_remove_device+0x34f/0x420 drivers/base/bus.c:579
 device_del+0x57c/0x9b0 drivers/base/core.c:3855
 usb_disable_device+0x3c5/0x860 drivers/usb/core/message.c:1418
 usb_disconnect+0x340/0x960 drivers/usb/core/hub.c:2316
 hub_port_connect drivers/usb/core/hub.c:5371 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5671 [inline]
 port_event drivers/usb/core/hub.c:5831 [inline]
 hub_event+0x1d2a/0x50f0 drivers/usb/core/hub.c:5913
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319
 worker_thread+0x870/0xd50 kernel/workqueue.c:3400
 kthread+0x7b7/0x940 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 21244:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x9d/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __kmalloc_cache_noprof+0x236/0x370 mm/slub.c:4372
 kmalloc_noprof include/linux/slab.h:905 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 em28xx_v4l2_init+0xfd/0x2f70 drivers/media/usb/em28xx/em28xx-video.c:2532
 em28xx_init_extension+0x120/0x1c0 drivers/media/usb/em28xx/em28xx-core.c:1117
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319
 worker_thread+0x870/0xd50 kernel/workqueue.c:3400
 kthread+0x7b7/0x940 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Freed by task 21244:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2398 [inline]
 slab_free mm/slub.c:4656 [inline]
 kfree+0x198/0x430 mm/slub.c:4855
 em28xx_free_v4l2 drivers/media/usb/em28xx/em28xx-video.c:2118 [inline]
 kref_put include/linux/kref.h:65 [inline]
 em28xx_v4l2_init+0x16fc/0x2f70 drivers/media/usb/em28xx/em28xx-video.c:2901
 em28xx_init_extension+0x120/0x1c0 drivers/media/usb/em28xx/em28xx-core.c:1117
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319
 worker_thread+0x870/0xd50 kernel/workqueue.c:3400
 kthread+0x7b7/0x940 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

The buggy address belongs to the object at ffff8880338f8000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 528 bytes inside of
 freed 8192-byte region [ffff8880338f8000, ffff8880338fa000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x338f8
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801b042280 ffffea0001717000 dead000000000005
raw: 0000000000000000 0000000080020002 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801b042280 ffffea0001717000 dead000000000005
head: 0000000000000000 0000000080020002 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea0000ce3e01 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0x152820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_HARDWALL), pid 6198, tgid 6198 (kworker/u8:9), ts 2450315180223, free_ts 2449971528254
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1718
 prep_new_page mm/page_alloc.c:1726 [inline]
 get_page_from_freelist+0x360a/0x37a0 mm/page_alloc.c:3688
 __alloc_frozen_pages_noprof+0x211/0x5b0 mm/page_alloc.c:4970
 alloc_pages_mpol+0x339/0x690 mm/mempolicy.c:2301
 alloc_slab_page mm/slub.c:2468 [inline]
 allocate_slab+0x8f/0x3b0 mm/slub.c:2632
 new_slab mm/slub.c:2686 [inline]
 ___slab_alloc+0xc3b/0x1500 mm/slub.c:3872
 __slab_alloc+0x58/0xa0 mm/slub.c:3962
 __slab_alloc_node mm/slub.c:4037 [inline]
 slab_alloc_node mm/slub.c:4198 [inline]
 __do_kmalloc_node mm/slub.c:4340 [inline]
 __kmalloc_noprof+0x2ea/0x4d0 mm/slub.c:4353
 kmalloc_noprof include/linux/slab.h:909 [inline]
 n_hdlc_tty_receive+0x1ce/0x4e0 drivers/tty/n_hdlc.c:393
 tty_ldisc_receive_buf+0x11f/0x170 drivers/tty/tty_buffer.c:391
 tty_port_default_receive_buf+0x6d/0xa0 drivers/tty/tty_port.c:37
 receive_buf drivers/tty/tty_buffer.c:445 [inline]
 flush_to_ldisc+0x32b/0x860 drivers/tty/tty_buffer.c:495
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319
 worker_thread+0x870/0xd50 kernel/workqueue.c:3400
 kthread+0x7b7/0x940 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
page last free pid 27840 tgid 27840 stack trace:
 create_dummy_stack mm/page_owner.c:94 [inline]
 register_dummy_stack+0x8e/0xe0 mm/page_owner.c:100
 init_page_owner+0x3e/0x790 mm/page_owner.c:118
 invoke_init_callbacks mm/page_ext.c:148 [inline]
 page_ext_init+0x731/0x790 mm/page_ext.c:497
 mm_core_init+0x5b/0x70 mm/mm_init.c:2784

Memory state around the buggy address:
 ffff8880338f8100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880338f8180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880338f8200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                         ^
 ffff8880338f8280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880338f8300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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