==================================================================
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+0x56/0x110 drivers/media/usb/as102/as102_usb_drv.c:456
Write of size 4 at addr ffff88813affc150 by task syz.6.6168/31807

CPU: 1 UID: 0 PID: 31807 Comm: syz.6.6168 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xcd/0x630 mm/kasan/report.c:482
 kasan_report+0xe0/0x110 mm/kasan/report.c:595
 check_region_inline mm/kasan/generic.c:194 [inline]
 kasan_check_range+0x100/0x1b0 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+0x56/0x110 drivers/media/usb/as102/as102_usb_drv.c:456
 __fput+0x402/0xb70 fs/file_table.c:468
 task_work_run+0x150/0x240 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop+0xc9/0xe0 kernel/entry/common.c:43
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
 do_syscall_64+0x40f/0x4d0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f609e25eec9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffcb076a0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 0000000000359839 RCX: 00007f609e25eec9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f609e4b7da0 R08: 0000000000000001 R09: 00000007b076a3df
R10: 0000001b30120000 R11: 0000000000000246 R12: 00007f609e4b5fac
R13: 00007f609e4b5fa0 R14: ffffffffffffffff R15: 00007ffcb076a200
 </TASK>

Allocated by task 19929:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
 kasan_save_track+0x14/0x30 mm/kasan/common.c:77
 poison_kmalloc_redzone mm/kasan/common.c:400 [inline]
 __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:417
 kmalloc_noprof include/linux/slab.h:957 [inline]
 kzalloc_noprof include/linux/slab.h:1094 [inline]
 as102_usb_probe+0x54/0xb00 drivers/media/usb/as102/as102_usb_drv.c:348
 usb_probe_interface+0x303/0xa40 drivers/usb/core/driver.c:396
 call_driver_probe drivers/base/dd.c:581 [inline]
 really_probe+0x241/0xa90 drivers/base/dd.c:659
 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:801
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:831
 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:959
 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:462
 __device_attach+0x1e4/0x4b0 drivers/base/dd.c:1031
 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:537
 device_add+0x1148/0x1aa0 drivers/base/core.c:3689
 usb_set_configuration+0x1187/0x1e20 drivers/usb/core/message.c:2210
 usb_generic_driver_probe+0xb1/0x110 drivers/usb/core/generic.c:250
 usb_probe_device+0xec/0x3e0 drivers/usb/core/driver.c:291
 call_driver_probe drivers/base/dd.c:581 [inline]
 really_probe+0x241/0xa90 drivers/base/dd.c:659
 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:801
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:831
 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:959
 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:462
 __device_attach+0x1e4/0x4b0 drivers/base/dd.c:1031
 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:537
 device_add+0x1148/0x1aa0 drivers/base/core.c:3689
 usb_new_device+0xd07/0x1a60 drivers/usb/core/hub.c:2689
 hub_port_connect drivers/usb/core/hub.c:5561 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5701 [inline]
 port_event drivers/usb/core/hub.c:5865 [inline]
 hub_event+0x2fce/0x5060 drivers/usb/core/hub.c:5947
 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3263
 process_scheduled_works kernel/workqueue.c:3346 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x56a/0x700 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Freed by task 19929:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
 kasan_save_track+0x14/0x30 mm/kasan/common.c:77
 __kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:587
 kasan_save_free_info mm/kasan/kasan.h:406 [inline]
 poison_slab_object mm/kasan/common.c:252 [inline]
 __kasan_slab_free+0x43/0x70 mm/kasan/common.c:284
 kasan_slab_free include/linux/kasan.h:234 [inline]
 slab_free_hook mm/slub.c:2515 [inline]
 slab_free mm/slub.c:6574 [inline]
 kfree+0x288/0x670 mm/slub.c:6781
 as102_usb_probe+0x697/0xb00 drivers/media/usb/as102/as102_usb_drv.c:410
 usb_probe_interface+0x303/0xa40 drivers/usb/core/driver.c:396
 call_driver_probe drivers/base/dd.c:581 [inline]
 really_probe+0x241/0xa90 drivers/base/dd.c:659
 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:801
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:831
 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:959
 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:462
 __device_attach+0x1e4/0x4b0 drivers/base/dd.c:1031
 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:537
 device_add+0x1148/0x1aa0 drivers/base/core.c:3689
 usb_set_configuration+0x1187/0x1e20 drivers/usb/core/message.c:2210
 usb_generic_driver_probe+0xb1/0x110 drivers/usb/core/generic.c:250
 usb_probe_device+0xec/0x3e0 drivers/usb/core/driver.c:291
 call_driver_probe drivers/base/dd.c:581 [inline]
 really_probe+0x241/0xa90 drivers/base/dd.c:659
 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:801
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:831
 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:959
 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:462
 __device_attach+0x1e4/0x4b0 drivers/base/dd.c:1031
 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:537
 device_add+0x1148/0x1aa0 drivers/base/core.c:3689
 usb_new_device+0xd07/0x1a60 drivers/usb/core/hub.c:2689
 hub_port_connect drivers/usb/core/hub.c:5561 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5701 [inline]
 port_event drivers/usb/core/hub.c:5865 [inline]
 hub_event+0x2fce/0x5060 drivers/usb/core/hub.c:5947
 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3263
 process_scheduled_works kernel/workqueue.c:3346 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x56a/0x700 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 ffff88813affc000
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 336 bytes inside of
 freed 4096-byte region [ffff88813affc000, ffff88813affd000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x13aff8
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0x200000000000040(head|node=0|zone=2)
page_type: f5(slab)
raw: 0200000000000040 ffff888100042140 0000000000000000 dead000000000001
raw: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000
head: 0200000000000040 ffff888100042140 0000000000000000 dead000000000001
head: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000
head: 0200000000000003 ffffea0004ebfe01 00000000ffffffff 00000000ffffffff
head: 0000000000000000 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 5550, tgid 5550 (kworker/1:7), ts 996884121199, free_ts 996066690953
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1850
 prep_new_page mm/page_alloc.c:1858 [inline]
 get_page_from_freelist+0x1003/0x2dc0 mm/page_alloc.c:3884
 __alloc_frozen_pages_noprof+0x259/0x21f0 mm/page_alloc.c:5183
 alloc_pages_mpol+0xe4/0x410 mm/mempolicy.c:2416
 alloc_slab_page mm/slub.c:3031 [inline]
 allocate_slab mm/slub.c:3204 [inline]
 new_slab+0x24a/0x360 mm/slub.c:3258
 ___slab_alloc+0xd73/0x1a70 mm/slub.c:4628
 __slab_alloc.constprop.0+0x63/0x110 mm/slub.c:4747
 __slab_alloc_node mm/slub.c:4823 [inline]
 slab_alloc_node mm/slub.c:5234 [inline]
 __kmalloc_cache_noprof+0x3c8/0x750 mm/slub.c:5720
 kmalloc_noprof include/linux/slab.h:957 [inline]
 kzalloc_noprof include/linux/slab.h:1094 [inline]
 kobject_uevent_env+0x265/0x1870 lib/kobject_uevent.c:540
 device_add+0x10dd/0x1aa0 drivers/base/core.c:3670
 cdev_device_add+0xc2/0x1e0 fs/char_dev.c:556
 evdev_connect+0x3a4/0x4c0 drivers/input/evdev.c:1383
 input_attach_handler.isra.0+0x176/0x250 drivers/input/input.c:994
 input_register_device+0xab9/0x1180 drivers/input/input.c:2378
 usbtouch_probe+0x1033/0x1dd0 drivers/input/touchscreen/usbtouchscreen.c:1579
 usb_probe_interface+0x303/0xa40 drivers/usb/core/driver.c:396
page last free pid 5550 tgid 5550 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1394 [inline]
 __free_frozen_pages+0x78f/0x1000 mm/page_alloc.c:2906
 discard_slab mm/slub.c:3302 [inline]
 __put_partials+0x130/0x170 mm/slub.c:3849
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x4e/0x70 mm/kasan/common.c:352
 kasan_slab_alloc include/linux/kasan.h:252 [inline]
 slab_post_alloc_hook mm/slub.c:4947 [inline]
 slab_alloc_node mm/slub.c:5246 [inline]
 __kmalloc_cache_noprof+0x284/0x750 mm/slub.c:5720
 kmalloc_noprof include/linux/slab.h:957 [inline]
 m920x_rc_query+0x58/0x770 drivers/media/usb/dvb-usb/m920x.c:184
 legacy_dvb_usb_read_remote_control+0x10c/0x4f0 drivers/media/usb/dvb-usb/dvb-usb-remote.c:123
 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3263
 process_scheduled_works kernel/workqueue.c:3346 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x56a/0x700 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Memory state around the buggy address:
 ffff88813affc000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88813affc080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88813affc100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                 ^
 ffff88813affc180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88813affc200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================