==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:96 [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 ffff8880773a8150 by task syz.4.6718/32073

CPU: 1 UID: 0 PID: 32073 Comm: syz.4.6718 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xca/0x240 mm/kasan/report.c:482
 kasan_report+0x118/0x150 mm/kasan/report.c:595
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x2b0/0x2c0 mm/kasan/generic.c:200
 instrument_atomic_read_write include/linux/instrumented.h:96 [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+0x44c/0xa70 fs/file_table.c:468
 task_work_run+0x1d4/0x260 kernel/task_work.c:233
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x694/0x22f0 kernel/exit.c:971
 do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
 get_signal+0x1285/0x1340 kernel/signal.c:3034
 arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
 exit_to_user_mode_loop+0x87/0x4e0 kernel/entry/common.c:75
 __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_work include/linux/entry-common.h:159 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
 do_syscall_64+0x2c1/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f95af38f749
Code: Unable to access opcode bytes at 0x7f95af38f71f.
RSP: 002b:00007f95b02c7038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: 0000000000000116 RBX: 00007f95af5e5fa0 RCX: 00007f95af38f749
RDX: 0000000000000318 RSI: 00002000000bd000 RDI: 0000000000000008
RBP: 00007f95af413f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f95af5e6038 R14: 00007f95af5e5fa0 R15: 00007f95af70fa28
 </TASK>

Allocated by task 30391:
 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+0x3e2/0x700 mm/slub.c:5776
 kmalloc_noprof include/linux/slab.h:957 [inline]
 kzalloc_noprof include/linux/slab.h:1094 [inline]
 as102_usb_probe+0x5b/0x6e0 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+0x26d/0xad0 drivers/base/dd.c:659
 __driver_probe_device+0x18c/0x320 drivers/base/dd.c:801
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:831
 __device_attach_driver+0x279/0x430 drivers/base/dd.c:959
 bus_for_each_drv+0x251/0x2e0 drivers/base/bus.c:500
 __device_attach+0x2b8/0x430 drivers/base/dd.c:1031
 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1086
 bus_probe_device+0x12a/0x220 drivers/base/bus.c:574
 device_add+0x7b6/0xb80 drivers/base/core.c:3689
 usb_set_configuration+0x1a87/0x2110 drivers/usb/core/message.c:2210
 usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:250
 usb_probe_device+0x1c4/0x3c0 drivers/usb/core/driver.c:291
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x26d/0xad0 drivers/base/dd.c:659
 __driver_probe_device+0x18c/0x320 drivers/base/dd.c:801
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:831
 __device_attach_driver+0x279/0x430 drivers/base/dd.c:959
 bus_for_each_drv+0x251/0x2e0 drivers/base/bus.c:500
 __device_attach+0x2b8/0x430 drivers/base/dd.c:1031
 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1086
 bus_probe_device+0x12a/0x220 drivers/base/bus.c:574
 device_add+0x7b6/0xb80 drivers/base/core.c:3689
 usb_new_device+0xa39/0x1720 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+0x29b1/0x4ef0 drivers/usb/core/hub.c:5953
 process_one_work kernel/workqueue.c:3257 [inline]
 process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

Freed by task 30391:
 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:2540 [inline]
 slab_free mm/slub.c:6670 [inline]
 kfree+0x1c0/0x660 mm/slub.c:6878
 as102_usb_probe+0x5d0/0x6e0 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+0x26d/0xad0 drivers/base/dd.c:659
 __driver_probe_device+0x18c/0x320 drivers/base/dd.c:801
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:831
 __device_attach_driver+0x279/0x430 drivers/base/dd.c:959
 bus_for_each_drv+0x251/0x2e0 drivers/base/bus.c:500
 __device_attach+0x2b8/0x430 drivers/base/dd.c:1031
 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1086
 bus_probe_device+0x12a/0x220 drivers/base/bus.c:574
 device_add+0x7b6/0xb80 drivers/base/core.c:3689
 usb_set_configuration+0x1a87/0x2110 drivers/usb/core/message.c:2210
 usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:250
 usb_probe_device+0x1c4/0x3c0 drivers/usb/core/driver.c:291
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x26d/0xad0 drivers/base/dd.c:659
 __driver_probe_device+0x18c/0x320 drivers/base/dd.c:801
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:831
 __device_attach_driver+0x279/0x430 drivers/base/dd.c:959
 bus_for_each_drv+0x251/0x2e0 drivers/base/bus.c:500
 __device_attach+0x2b8/0x430 drivers/base/dd.c:1031
 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1086
 bus_probe_device+0x12a/0x220 drivers/base/bus.c:574
 device_add+0x7b6/0xb80 drivers/base/core.c:3689
 usb_new_device+0xa39/0x1720 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+0x29b1/0x4ef0 drivers/usb/core/hub.c:5953
 process_one_work kernel/workqueue.c:3257 [inline]
 process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

The buggy address belongs to the object at ffff8880773a8000
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 336 bytes inside of
 freed 4096-byte region [ffff8880773a8000, ffff8880773a9000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x773a8
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 ffff88813ffa7140 ffffea0000d69200 dead000000000002
raw: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88813ffa7140 ffffea0000d69200 dead000000000002
head: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea0001dcea01 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 5201, tgid 5201 (udevd), ts 51397458805, free_ts 31509843662
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x234/0x290 mm/page_alloc.c:1857
 prep_new_page mm/page_alloc.c:1865 [inline]
 get_page_from_freelist+0x24e0/0x2580 mm/page_alloc.c:3915
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486
 alloc_slab_page mm/slub.c:3075 [inline]
 allocate_slab+0x86/0x3b0 mm/slub.c:3248
 new_slab mm/slub.c:3302 [inline]
 ___slab_alloc+0xe53/0x1820 mm/slub.c:4656
 __slab_alloc+0x65/0x100 mm/slub.c:4779
 __slab_alloc_node mm/slub.c:4855 [inline]
 slab_alloc_node mm/slub.c:5251 [inline]
 __do_kmalloc_node mm/slub.c:5656 [inline]
 __kmalloc_noprof+0x47d/0x800 mm/slub.c:5669
 kmalloc_noprof include/linux/slab.h:961 [inline]
 tomoyo_realpath_from_path+0xe3/0x5d0 security/tomoyo/realpath.c:251
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_check_open_permission+0x1c1/0x3b0 security/tomoyo/file.c:771
 security_file_open+0xb1/0x270 security/security.c:2636
 do_dentry_open+0x34e/0x1420 fs/open.c:939
 vfs_open+0x3b/0x340 fs/open.c:1094
 do_open fs/namei.c:4628 [inline]
 path_openat+0x340e/0x3dd0 fs/namei.c:4787
 do_filp_open+0x1fa/0x410 fs/namei.c:4814
 do_sys_openat2+0x121/0x200 fs/open.c:1430
page last free pid 1 tgid 1 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1406 [inline]
 __free_frozen_pages+0xbc8/0xd30 mm/page_alloc.c:2943
 __free_pages mm/page_alloc.c:5329 [inline]
 free_contig_range+0x1bd/0x490 mm/page_alloc.c:7197
 destroy_args+0x69/0x660 mm/debug_vm_pgtable.c:983
 debug_vm_pgtable+0x38f/0x3a0 mm/debug_vm_pgtable.c:1372
 do_one_initcall+0x1f1/0x800 init/main.c:1378
 do_initcall_level+0x104/0x190 init/main.c:1440
 do_initcalls+0x59/0xa0 init/main.c:1456
 kernel_init_freeable+0x2a7/0x3d0 init/main.c:1688
 kernel_init+0x1d/0x1d0 init/main.c:1578
 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

Memory state around the buggy address:
 ffff8880773a8000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880773a8080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880773a8100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                 ^
 ffff8880773a8180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880773a8200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================