==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:112 [inline]
BUG: KASAN: slab-use-after-free in atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:400 [inline]
BUG: KASAN: slab-use-after-free in __refcount_sub_and_test include/linux/refcount.h:389 [inline]
BUG: KASAN: slab-use-after-free in __refcount_dec_and_test include/linux/refcount.h:432 [inline]
BUG: KASAN: slab-use-after-free in refcount_dec_and_test include/linux/refcount.h:450 [inline]
BUG: KASAN: slab-use-after-free in kref_put include/linux/kref.h:64 [inline]
BUG: KASAN: slab-use-after-free in as102_release+0x52/0xe0 drivers/media/usb/as102/as102_usb_drv.c:456
Write of size 4 at addr ffff888053d14150 by task syz.8.2819/14716

CPU: 1 UID: 0 PID: 14716 Comm: syz.8.2819 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xba/0x230 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x264/0x2c0 mm/kasan/generic.c:200
 instrument_atomic_read_write include/linux/instrumented.h:112 [inline]
 atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:400 [inline]
 __refcount_sub_and_test include/linux/refcount.h:389 [inline]
 __refcount_dec_and_test include/linux/refcount.h:432 [inline]
 refcount_dec_and_test include/linux/refcount.h:450 [inline]
 kref_put include/linux/kref.h:64 [inline]
 as102_release+0x52/0xe0 drivers/media/usb/as102/as102_usb_drv.c:456
 __fput+0x44f/0xa70 fs/file_table.c:469
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x69b/0x2320 kernel/exit.c:971
 do_group_exit+0x21b/0x2d0 kernel/exit.c:1112
 get_signal+0x1284/0x1330 kernel/signal.c:3034
 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
 exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
 do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f93da19c799
Code: Unable to access opcode bytes at 0x7f93da19c76f.
RSP: 002b:00007f93da53fba8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffdfc RBX: 00000000000d6fb5 RCX: 00007f93da19c799
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f93da41609c
RBP: 0000000000000bea R08: 3fffffffffffffff R09: 0000000000000000
R10: 00007f93da53fcb0 R11: 0000000000000246 R12: 00007f93da53fcd0
R13: 00007f93da41609c R14: 00000000000d7b9f R15: 00007f93da53fcb0
 </TASK>

Allocated by task 8565:
 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:398 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_noprof+0x31c/0x660 mm/slub.c:5358
 kmalloc_noprof include/linux/slab.h:950 [inline]
 kzalloc_noprof include/linux/slab.h:1188 [inline]
 as102_usb_probe+0x5b/0x6d0 drivers/media/usb/as102/as102_usb_drv.c:348
 usb_probe_interface+0x668/0xc90 drivers/usb/core/driver.c:396
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x267/0xaf0 drivers/base/dd.c:661
 __driver_probe_device+0x18c/0x320 drivers/base/dd.c:803
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:833
 __device_attach_driver+0x2d4/0x4c0 drivers/base/dd.c:961
 bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500
 __device_attach+0x2c5/0x450 drivers/base/dd.c:1033
 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1088
 bus_probe_device+0x12a/0x220 drivers/base/bus.c:574
 device_add+0x7b6/0xb70 drivers/base/core.c:3689
 usb_set_configuration+0x1a87/0x2110 drivers/usb/core/message.c:2208
 usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:250
 usb_probe_device+0x1c4/0x3b0 drivers/usb/core/driver.c:291
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x267/0xaf0 drivers/base/dd.c:661
 __driver_probe_device+0x18c/0x320 drivers/base/dd.c:803
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:833
 __device_attach_driver+0x2d4/0x4c0 drivers/base/dd.c:961
 bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500
 __device_attach+0x2c5/0x450 drivers/base/dd.c:1033
 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1088
 bus_probe_device+0x12a/0x220 drivers/base/bus.c:574
 device_add+0x7b6/0xb70 drivers/base/core.c:3689
 usb_new_device+0xa08/0x16f0 drivers/usb/core/hub.c:2695
 hub_port_connect drivers/usb/core/hub.c:5567 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
 port_event drivers/usb/core/hub.c:5871 [inline]
 hub_event+0x2a1c/0x4f30 drivers/usb/core/hub.c:5953
 process_one_work kernel/workqueue.c:3275 [inline]
 process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358
 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
 kthread+0x388/0x470 kernel/kthread.c:467
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Freed by task 8565:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2692 [inline]
 slab_free mm/slub.c:6143 [inline]
 kfree+0x1c1/0x630 mm/slub.c:6461
 as102_usb_probe+0x5d0/0x6d0 drivers/media/usb/as102/as102_usb_drv.c:410
 usb_probe_interface+0x668/0xc90 drivers/usb/core/driver.c:396
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x267/0xaf0 drivers/base/dd.c:661
 __driver_probe_device+0x18c/0x320 drivers/base/dd.c:803
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:833
 __device_attach_driver+0x2d4/0x4c0 drivers/base/dd.c:961
 bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500
 __device_attach+0x2c5/0x450 drivers/base/dd.c:1033
 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1088
 bus_probe_device+0x12a/0x220 drivers/base/bus.c:574
 device_add+0x7b6/0xb70 drivers/base/core.c:3689
 usb_set_configuration+0x1a87/0x2110 drivers/usb/core/message.c:2208
 usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:250
 usb_probe_device+0x1c4/0x3b0 drivers/usb/core/driver.c:291
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x267/0xaf0 drivers/base/dd.c:661
 __driver_probe_device+0x18c/0x320 drivers/base/dd.c:803
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:833
 __device_attach_driver+0x2d4/0x4c0 drivers/base/dd.c:961
 bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500
 __device_attach+0x2c5/0x450 drivers/base/dd.c:1033
 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1088
 bus_probe_device+0x12a/0x220 drivers/base/bus.c:574
 device_add+0x7b6/0xb70 drivers/base/core.c:3689
 usb_new_device+0xa08/0x16f0 drivers/usb/core/hub.c:2695
 hub_port_connect drivers/usb/core/hub.c:5567 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
 port_event drivers/usb/core/hub.c:5871 [inline]
 hub_event+0x2a1c/0x4f30 drivers/usb/core/hub.c:5953
 process_one_work kernel/workqueue.c:3275 [inline]
 process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358
 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
 kthread+0x388/0x470 kernel/kthread.c:467
 ret_from_fork+0x51e/0xb90 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 ffff888053d14000
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 336 bytes inside of
 freed 4096-byte region [ffff888053d14000, ffff888053d15000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x53d10
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 ffff88813fea9140 dead000000000100 dead000000000122
raw: 0000000000000000 0000000800040004 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88813fea9140 dead000000000100 dead000000000122
head: 0000000000000000 0000000800040004 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea00014f4401 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 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5192, tgid 5192 (udevd), ts 36284916856, free_ts 34976289850
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x231/0x280 mm/page_alloc.c:1889
 prep_new_page mm/page_alloc.c:1897 [inline]
 get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3962
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250
 alloc_slab_page mm/slub.c:3269 [inline]
 allocate_slab+0x77/0x660 mm/slub.c:3458
 new_slab mm/slub.c:3516 [inline]
 refill_objects+0x331/0x3c0 mm/slub.c:7153
 refill_sheaf mm/slub.c:2818 [inline]
 __pcs_replace_empty_main+0x2b9/0x620 mm/slub.c:4592
 alloc_from_pcs mm/slub.c:4695 [inline]
 slab_alloc_node mm/slub.c:4829 [inline]
 __do_kmalloc_node mm/slub.c:5237 [inline]
 __kmalloc_noprof+0x474/0x760 mm/slub.c:5250
 kmalloc_noprof include/linux/slab.h:954 [inline]
 tomoyo_realpath_from_path+0xe3/0x5d0 security/tomoyo/realpath.c:251
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path_perm+0x283/0x560 security/tomoyo/file.c:827
 security_inode_getattr+0x12b/0x310 security/security.c:1869
 vfs_getattr fs/stat.c:259 [inline]
 vfs_fstat fs/stat.c:281 [inline]
 __do_sys_newfstat fs/stat.c:551 [inline]
 __se_sys_newfstat fs/stat.c:546 [inline]
 __x64_sys_newfstat+0x13b/0x270 fs/stat.c:546
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 5201 tgid 5201 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1433 [inline]
 __free_frozen_pages+0xc2b/0xdb0 mm/page_alloc.c:2978
 __slab_free+0x263/0x2b0 mm/slub.c:5551
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4515 [inline]
 slab_alloc_node mm/slub.c:4844 [inline]
 __do_kmalloc_node mm/slub.c:5237 [inline]
 __kvmalloc_node_noprof+0x4d7/0x8a0 mm/slub.c:6730
 seq_buf_alloc fs/seq_file.c:39 [inline]
 seq_read_iter+0x202/0xe10 fs/seq_file.c:211
 new_sync_read fs/read_write.c:493 [inline]
 vfs_read+0x582/0xa70 fs/read_write.c:574
 ksys_read+0x150/0x270 fs/read_write.c:717
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888053d14000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888053d14080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888053d14100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                 ^
 ffff888053d14180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888053d14200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================