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BUG: KASAN: slab-use-after-free in v4l2_open+0x395/0x3a0
Read of size 4 at addr ffff888112d4c860 by task v4l_id/7295

CPU: 0 UID: 0 PID: 7295 Comm: v4l_id Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150
 print_address_description+0x55/0x1e0
 print_report+0x58/0x70
 kasan_report+0x117/0x150
 v4l2_open+0x395/0x3a0
 chrdev_open+0x4cd/0x5e0
 do_dentry_open+0x785/0x14e0
 vfs_open+0x3b/0x340
 path_openat+0x2e08/0x3860
 do_file_open+0x23e/0x4a0
 do_sys_openat2+0x113/0x200
 __x64_sys_openat+0x138/0x170
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6fd4d169a4
Code: 24 20 48 8d 44 24 30 48 89 44 24 28 64 8b 04 25 18 00 00 00 85 c0 75 2c 44 89 e2 48 89 ee bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 76 60 48 8b 15 55 a4 0d 00 f7 d8 64 89 02 48 83
RSP: 002b:00007ffe61794270 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007ffe61794488 RCX: 00007f6fd4d169a4
RDX: 0000000000000000 RSI: 00007ffe61795f1c RDI: 00000000ffffff9c
RBP: 00007ffe61795f1c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffe617944a0 R14: 00005620aabba670 R15: 00007f6fd52e2a80
 </TASK>

Allocated by task 799:
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_cache_noprof+0x31c/0x660
 em28xx_v4l2_init+0x10b/0x2eb0
 em28xx_init_extension+0x120/0x1c0
 process_scheduled_works+0xb5d/0x1860
 worker_thread+0xa53/0xfc0
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30

Freed by task 799:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x5c/0x80
 kfree+0x1c5/0x640
 em28xx_v4l2_init+0x1685/0x2eb0
 em28xx_init_extension+0x120/0x1c0
 process_scheduled_works+0xb5d/0x1860
 worker_thread+0xa53/0xfc0
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30

The buggy address belongs to the object at ffff888112d4c000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 2144 bytes inside of
 freed 8192-byte region [ffff888112d4c000, ffff888112d4e000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x112d48
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x17ff00000000040(head|node=0|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 017ff00000000040 ffff888100042280 dead000000000100 dead000000000122
raw: 0000000000000000 0000000800020002 00000000f5000000 0000000000000000
head: 017ff00000000040 ffff888100042280 dead000000000100 dead000000000122
head: 0000000000000000 0000000800020002 00000000f5000000 0000000000000000
head: 017ff00000000003 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 0xd28c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 6691, tgid 6691 (syz-executor), ts 121308208700, free_ts 121209377267
 post_alloc_hook+0x231/0x280
 get_page_from_freelist+0x24ba/0x2540
 __alloc_frozen_pages_noprof+0x18d/0x380
 allocate_slab+0x77/0x660
 refill_objects+0x339/0x3d0
 __pcs_replace_empty_main+0x321/0x720
 __kvmalloc_node_noprof+0x657/0x8a0
 wg_packet_queue_init+0xbc/0x320
 wg_newlink+0x326/0x670
 rtnl_newlink_create+0x329/0xb70
 rtnl_newlink+0x166a/0x1bb0
 rtnetlink_rcv_msg+0x7d5/0xbe0
 netlink_rcv_skb+0x232/0x4b0
 netlink_unicast+0x75c/0x8e0
 netlink_sendmsg+0x813/0xb40
 __sys_sendto+0x672/0x710
page last free pid 10 tgid 10 stack trace:
 __free_frozen_pages+0xbc7/0xd30
 __slab_free+0x274/0x2c0
 qlist_free_all+0x99/0x100
 kasan_quarantine_reduce+0x148/0x160
 __kasan_slab_alloc+0x22/0x80
 kmem_cache_alloc_noprof+0x2bc/0x650
 __kernfs_new_node+0xea/0x970
 kernfs_new_node+0x102/0x210
 kernfs_create_dir_ns+0x44/0x130
 internal_create_group+0x425/0x1180
 dpm_sysfs_add+0x6a/0x270
 device_add+0x4d8/0xbb0
 usb_new_device+0xa08/0x16f0
 hub_event+0x2a1c/0x4f30
 process_scheduled_works+0xb5d/0x1860
 worker_thread+0xa53/0xfc0

Memory state around the buggy address:
 ffff888112d4c700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888112d4c780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888112d4c800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                       ^
 ffff888112d4c880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888112d4c900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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