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BUG: KASAN: slab-use-after-free in v4l2_open+0x397/0x3a0 drivers/media/v4l2-core/v4l2-dev.c:444
Read of size 4 at addr ffff888023694858 by task v4l_id/6274

CPU: 1 UID: 0 PID: 6274 Comm: v4l_id Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/15/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description+0x55/0x1e0 mm/kasan/report.c:378
 print_report+0x58/0x70 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 v4l2_open+0x397/0x3a0 drivers/media/v4l2-core/v4l2-dev.c:444
 chrdev_open+0x4d9/0x600 fs/char_dev.c:413
 do_dentry_open+0x80e/0x1360 fs/open.c:1000
 vfs_open_consume+0x4a/0x350 fs/open.c:1131
 do_open fs/namei.c:4851 [inline]
 path_openat+0x16fc/0x20f0 fs/namei.c:5016
 do_file_open+0x23e/0x4a0 fs/namei.c:5045
 do_sys_openat2+0x115/0x200 fs/open.c:1443
 do_sys_open fs/open.c:1449 [inline]
 __do_sys_openat fs/open.c:1465 [inline]
 __se_sys_openat fs/open.c:1460 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1460
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe1f62a7407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007fffba78f940 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fe1f6a80880 RCX: 00007fe1f62a7407
RDX: 0000000000000000 RSI: 00007fffba790f1c RDI: ffffffffffffff9c
RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 00007fffba78fb90 R14: 00007fe1f6be7000 R15: 0000560f3269d4d8
 </TASK>

Allocated by task 5718:
 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:409 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:426
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_noprof+0x31c/0x600 mm/slub.c:5680
 _kmalloc_noprof include/linux/slab.h:991 [inline]
 _kzalloc_noprof include/linux/slab.h:1312 [inline]
 em28xx_v4l2_init+0xff/0x31f0 drivers/media/usb/em28xx/em28xx-video.c:2751
 em28xx_init_extension+0x120/0x1d0 drivers/media/usb/em28xx/em28xx-core.c:1245
 process_one_work kernel/workqueue.c:3495 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3578
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3659
 kthread+0x38b/0x480 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Freed by task 5752:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:264 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:296
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2780 [inline]
 slab_free mm/slub.c:6630 [inline]
 kfree+0x1c5/0x650 mm/slub.c:6923
 em28xx_free_v4l2+0x77/0xf0 drivers/media/usb/em28xx/em28xx-video.c:2337
 v4l2_device_release drivers/media/v4l2-core/v4l2-device.c:51 [inline]
 kref_put include/linux/kref.h:65 [inline]
 v4l2_device_put+0x81/0xd0 drivers/media/v4l2-core/v4l2-device.c:56
 em28xx_v4l2_fini+0x1f3/0x3e0 drivers/media/usb/em28xx/em28xx-video.c:2465
 em28xx_close_extension+0xde/0x390 drivers/media/usb/em28xx/em28xx-core.c:1262
 em28xx_usb_disconnect+0x16b/0x2f0 drivers/media/usb/em28xx/em28xx-cards.c:4489
 usb_unbind_interface+0x295/0x9c0 drivers/usb/core/driver.c:460
 device_remove drivers/base/dd.c:619 [inline]
 __device_release_driver drivers/base/dd.c:1357 [inline]
 device_release_driver_internal+0x48d/0x7d0 drivers/base/dd.c:1380
 bus_remove_device+0x444/0x560 drivers/base/bus.c:678
 device_del+0x524/0x8f0 drivers/base/core.c:3967
 usb_disable_device+0x3d4/0x8d0 drivers/usb/core/message.c:1484
 usb_disconnect+0x346/0x9a0 drivers/usb/core/hub.c:2355
 hub_port_connect drivers/usb/core/hub.c:5425 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5725 [inline]
 port_event drivers/usb/core/hub.c:5889 [inline]
 hub_event+0x1bbb/0x4d30 drivers/usb/core/hub.c:5971
 process_one_work kernel/workqueue.c:3495 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3578
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3659
 kthread+0x38b/0x480 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 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 ffff888023694000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 2136 bytes inside of
 freed 8192-byte region [ffff888023694000, ffff888023696000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x23690
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88813ff26280 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88813ff26280 dead000000000100 dead000000000122
head: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000
head: 00fff00000000003 fffffffffffffe01 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 2643602755
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1859
 prep_new_page mm/page_alloc.c:1867 [inline]
 get_page_from_freelist+0x2224/0x2290 mm/page_alloc.c:3940
 __alloc_frozen_pages_noprof+0x1fe/0x410 mm/page_alloc.c:5464
 alloc_slab_page mm/slub.c:3384 [inline]
 allocate_slab+0x7d/0x5e0 mm/slub.c:3499
 new_slab mm/slub.c:3550 [inline]
 refill_objects+0x2d5/0x350 mm/slub.c:7539
 refill_sheaf mm/slub.c:2917 [inline]
 __pcs_replace_empty_main+0x2c8/0x6c0 mm/slub.c:4811
 alloc_from_pcs mm/slub.c:4887 [inline]
 slab_alloc_node mm/slub.c:5021 [inline]
 __do_kmalloc_node mm/slub.c:5530 [inline]
 __kmalloc_noprof+0x476/0x710 mm/slub.c:5556
 _kmalloc_noprof include/linux/slab.h:995 [inline]
 _kzalloc_noprof include/linux/slab.h:1312 [inline]
 __hugetlb_cgroup_file_pre_init+0x9e/0x100 mm/hugetlb_cgroup.c:895
 hugetlb_cgroup_file_init+0x10/0xb0 mm/hugetlb_cgroup.c:911
 hugetlb_init+0x3d9/0x620 mm/hugetlb.c:4231
 do_one_initcall+0x250/0x870 init/main.c:1419
 do_initcall_level+0x10a/0x1a0 init/main.c:1481
 do_initcalls+0x59/0xa0 init/main.c:1497
 kernel_init_freeable+0x29d/0x3e0 init/main.c:1732
 kernel_init+0x22/0x1d0 init/main.c:1622
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888023694700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888023694780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888023694800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                    ^
 ffff888023694880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888023694900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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