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BUG: KASAN: use-after-free in atomic_fetch_sub include/asm-generic/atomic-instrumented.h:199 [inline]
BUG: KASAN: use-after-free in refcount_sub_and_test include/linux/refcount.h:253 [inline]
BUG: KASAN: use-after-free in refcount_dec_and_test include/linux/refcount.h:281 [inline]
BUG: KASAN: use-after-free in kref_put include/linux/kref.h:64 [inline]
BUG: KASAN: use-after-free in as102_release+0x58/0xd8 drivers/media/usb/as102/as102_usb_drv.c:458
Write of size 4 at addr ffff8881acbcc140 by task syz-executor.4/25738

CPU: 0 PID: 25738 Comm: syz-executor.4 Not tainted 5.6.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0xef/0x16e lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xd3/0x314 mm/kasan/report.c:374
 __kasan_report.cold+0x37/0x77 mm/kasan/report.c:506
 kasan_report+0xe/0x20 mm/kasan/common.c:641
 check_memory_region_inline mm/kasan/generic.c:185 [inline]
 check_memory_region+0x152/0x1c0 mm/kasan/generic.c:192
 atomic_fetch_sub include/asm-generic/atomic-instrumented.h:199 [inline]
 refcount_sub_and_test include/linux/refcount.h:253 [inline]
 refcount_dec_and_test include/linux/refcount.h:281 [inline]
 kref_put include/linux/kref.h:64 [inline]
 as102_release+0x58/0xd8 drivers/media/usb/as102/as102_usb_drv.c:458
 __fput+0x2d7/0x840 fs/file_table.c:280
 task_work_run+0x13f/0x1c0 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0xb8b/0x2c50 kernel/exit.c:801
 do_group_exit+0x125/0x340 kernel/exit.c:899
 get_signal+0x480/0x2470 kernel/signal.c:2734
 do_signal+0x88/0x1490 arch/x86/kernel/signal.c:813
 exit_to_usermode_loop+0x1a2/0x200 arch/x86/entry/common.c:160
 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:278 [inline]
 do_syscall_64+0x4e0/0x5a0 arch/x86/entry/common.c:304
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c2b7
Code: 48 83 c4 08 48 89 d8 5b 5d c3 66 0f 1f 84 00 00 00 00 00 48 89 e8 48 f7 d8 48 39 c3 0f 92 c0 eb 92 66 90 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 0d b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f745032a298 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: fffffffffffffe00 RBX: 0000000000000012 RCX: 000000000045c2b7
RDX: 00007f745032a400 RSI: 0000000040085503 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0100000042ef4200 R09: 0000000000000000
R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000bf5 R14: 00000000004c1e00 R15: 000000000076bf2c

Allocated by task 28704:
 save_stack+0x1b/0x80 mm/kasan/common.c:72
 set_track mm/kasan/common.c:80 [inline]
 __kasan_kmalloc mm/kasan/common.c:515 [inline]
 __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:488
 kmalloc include/linux/slab.h:555 [inline]
 kzalloc include/linux/slab.h:669 [inline]
 as102_usb_probe+0x4e/0x3d0 drivers/media/usb/as102/as102_usb_drv.c:350
 usb_probe_interface+0x310/0x800 drivers/usb/core/driver.c:361
 really_probe+0x290/0xac0 drivers/base/dd.c:551
 driver_probe_device+0x223/0x350 drivers/base/dd.c:724
 __device_attach_driver+0x1d1/0x290 drivers/base/dd.c:831
 bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:431
 __device_attach+0x217/0x390 drivers/base/dd.c:897
 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:491
 device_add+0x1459/0x1bf0 drivers/base/core.c:2487
 usb_set_configuration+0xe47/0x17d0 drivers/usb/core/message.c:2023
 generic_probe+0x9d/0xd5 drivers/usb/core/generic.c:210
 usb_probe_device+0xaf/0x140 drivers/usb/core/driver.c:266
 really_probe+0x290/0xac0 drivers/base/dd.c:551
 driver_probe_device+0x223/0x350 drivers/base/dd.c:724
 __device_attach_driver+0x1d1/0x290 drivers/base/dd.c:831
 bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:431
 __device_attach+0x217/0x390 drivers/base/dd.c:897
 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:491
 device_add+0x1459/0x1bf0 drivers/base/core.c:2487
 usb_new_device.cold+0x540/0xcd0 drivers/usb/core/hub.c:2538
 hub_port_connect drivers/usb/core/hub.c:5185 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5325 [inline]
 port_event drivers/usb/core/hub.c:5471 [inline]
 hub_event+0x21cb/0x4300 drivers/usb/core/hub.c:5553
 process_one_work+0x94b/0x1620 kernel/workqueue.c:2264
 worker_thread+0x96/0xe20 kernel/workqueue.c:2410
 kthread+0x318/0x420 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

Freed by task 28704:
 save_stack+0x1b/0x80 mm/kasan/common.c:72
 set_track mm/kasan/common.c:80 [inline]
 kasan_set_free_info mm/kasan/common.c:337 [inline]
 __kasan_slab_free+0x117/0x160 mm/kasan/common.c:476
 slab_free_hook mm/slub.c:1444 [inline]
 slab_free_freelist_hook mm/slub.c:1477 [inline]
 slab_free mm/slub.c:3024 [inline]
 kfree+0xd5/0x300 mm/slub.c:3976
 as102_usb_probe.cold+0x142/0x3bf drivers/media/usb/as102/as102_usb_drv.c:412
 usb_probe_interface+0x310/0x800 drivers/usb/core/driver.c:361
 really_probe+0x290/0xac0 drivers/base/dd.c:551
 driver_probe_device+0x223/0x350 drivers/base/dd.c:724
 __device_attach_driver+0x1d1/0x290 drivers/base/dd.c:831
 bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:431
 __device_attach+0x217/0x390 drivers/base/dd.c:897
 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:491
 device_add+0x1459/0x1bf0 drivers/base/core.c:2487
 usb_set_configuration+0xe47/0x17d0 drivers/usb/core/message.c:2023
 generic_probe+0x9d/0xd5 drivers/usb/core/generic.c:210
 usb_probe_device+0xaf/0x140 drivers/usb/core/driver.c:266
 really_probe+0x290/0xac0 drivers/base/dd.c:551
 driver_probe_device+0x223/0x350 drivers/base/dd.c:724
 __device_attach_driver+0x1d1/0x290 drivers/base/dd.c:831
 bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:431
 __device_attach+0x217/0x390 drivers/base/dd.c:897
 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:491
 device_add+0x1459/0x1bf0 drivers/base/core.c:2487
 usb_new_device.cold+0x540/0xcd0 drivers/usb/core/hub.c:2538
 hub_port_connect drivers/usb/core/hub.c:5185 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5325 [inline]
 port_event drivers/usb/core/hub.c:5471 [inline]
 hub_event+0x21cb/0x4300 drivers/usb/core/hub.c:5553
 process_one_work+0x94b/0x1620 kernel/workqueue.c:2264
 worker_thread+0x96/0xe20 kernel/workqueue.c:2410
 kthread+0x318/0x420 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

The buggy address belongs to the object at ffff8881acbcc000
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 320 bytes inside of
 4096-byte region [ffff8881acbcc000, ffff8881acbcd000)
The buggy address belongs to the page:
page:ffffea0006b2f200 refcount:1 mapcount:0 mapping:ffff8881da00c280 index:0x0 compound_mapcount: 0
flags: 0x200000000010200(slab|head)
raw: 0200000000010200 0000000000000000 0000000100000001 ffff8881da00c280
raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8881acbcc000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881acbcc080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8881acbcc100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                           ^
 ffff8881acbcc180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881acbcc200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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