usb 1-1: USB disconnect, device number 3
==================================================================
BUG: KASAN: use-after-free in hdm_disconnect+0xf4/0x18c drivers/most/most_usb.c:1125
Read of size 8 at addr ffff0000d16a58b0 by task kworker/0:11/4701

CPU: 0 PID: 4701 Comm: kworker/0:11 Not tainted 6.1.136-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: usb_hub_wq hub_event
Call trace:
 dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
 __dump_stack+0x30/0x40 lib/dump_stack.c:88
 dump_stack_lvl+0xf8/0x160 lib/dump_stack.c:106
 print_address_description+0x88/0x220 mm/kasan/report.c:316
 print_report+0x50/0x68 mm/kasan/report.c:427
 kasan_report+0xa8/0x100 mm/kasan/report.c:531
 __asan_report_load8_noabort+0x2c/0x38 mm/kasan/report_generic.c:351
 hdm_disconnect+0xf4/0x18c drivers/most/most_usb.c:1125
 usb_unbind_interface+0x1b8/0x750 drivers/usb/core/driver.c:458
 device_remove drivers/base/dd.c:550 [inline]
 __device_release_driver drivers/base/dd.c:1260 [inline]
 device_release_driver_internal+0x424/0x6d0 drivers/base/dd.c:1286
 device_release_driver+0x28/0x38 drivers/base/dd.c:1309
 bus_remove_device+0x294/0x388 drivers/base/bus.c:531
 device_del+0x568/0x96c drivers/base/core.c:3885
 usb_disable_device+0x33c/0x780 drivers/usb/core/message.c:1414
 usb_disconnect+0x284/0x790 drivers/usb/core/hub.c:2286
 hub_port_connect drivers/usb/core/hub.c:5333 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5629 [inline]
 port_event drivers/usb/core/hub.c:5785 [inline]
 hub_event+0x15e0/0x3dc4 drivers/usb/core/hub.c:5867
 process_one_work+0x7f4/0x13a8 kernel/workqueue.c:2292
 worker_thread+0x8c8/0xfbc kernel/workqueue.c:2439
 kthread+0x250/0x2d8 kernel/kthread.c:376
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:864

Allocated by task 4701:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4c/0x80 mm/kasan/common.c:52
 kasan_save_alloc_info+0x28/0x34 mm/kasan/generic.c:505
 ____kasan_kmalloc mm/kasan/common.c:374 [inline]
 __kasan_kmalloc+0xa0/0xb8 mm/kasan/common.c:383
 kasan_kmalloc include/linux/kasan.h:211 [inline]
 kmalloc_trace+0x7c/0x94 mm/slab_common.c:1031
 kmalloc include/linux/slab.h:563 [inline]
 kzalloc include/linux/slab.h:699 [inline]
 hdm_probe+0x9c/0x1044 drivers/most/most_usb.c:959
 usb_probe_interface+0x4fc/0x994 drivers/usb/core/driver.c:396
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x39c/0xae0 drivers/base/dd.c:639
 __driver_probe_device+0x180/0x314 drivers/base/dd.c:785
 driver_probe_device+0x78/0x330 drivers/base/dd.c:815
 __device_attach_driver+0x290/0x4e0 drivers/base/dd.c:943
 bus_for_each_drv+0x150/0x1d8 drivers/base/bus.c:429
 __device_attach+0x2a8/0x3d4 drivers/base/dd.c:1015
 device_initial_probe+0x24/0x34 drivers/base/dd.c:1064
 bus_probe_device+0xbc/0x1c4 drivers/base/bus.c:489
 device_add+0xb04/0xf94 drivers/base/core.c:3697
 usb_set_configuration+0x1598/0x1b0c drivers/usb/core/message.c:2165
 usb_generic_driver_probe+0x8c/0x144 drivers/usb/core/generic.c:238
 usb_probe_device+0x120/0x25c drivers/usb/core/driver.c:293
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x39c/0xae0 drivers/base/dd.c:639
 __driver_probe_device+0x180/0x314 drivers/base/dd.c:785
 driver_probe_device+0x78/0x330 drivers/base/dd.c:815
 __device_attach_driver+0x290/0x4e0 drivers/base/dd.c:943
 bus_for_each_drv+0x150/0x1d8 drivers/base/bus.c:429
 __device_attach+0x2a8/0x3d4 drivers/base/dd.c:1015
 device_initial_probe+0x24/0x34 drivers/base/dd.c:1064
 bus_probe_device+0xbc/0x1c4 drivers/base/bus.c:489
 device_add+0xb04/0xf94 drivers/base/core.c:3697
 usb_new_device+0x7f0/0x11c4 drivers/usb/core/hub.c:2631
 hub_port_connect drivers/usb/core/hub.c:5489 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5629 [inline]
 port_event drivers/usb/core/hub.c:5785 [inline]
 hub_event+0x21c8/0x3dc4 drivers/usb/core/hub.c:5867
 process_one_work+0x7f4/0x13a8 kernel/workqueue.c:2292
 worker_thread+0x8c8/0xfbc kernel/workqueue.c:2439
 kthread+0x250/0x2d8 kernel/kthread.c:376
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:864

Freed by task 4701:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4c/0x80 mm/kasan/common.c:52
 kasan_save_free_info+0x3c/0x60 mm/kasan/generic.c:516
 ____kasan_slab_free+0x148/0x1b0 mm/kasan/common.c:236
 __kasan_slab_free+0x18/0x28 mm/kasan/common.c:244
 kasan_slab_free include/linux/kasan.h:177 [inline]
 slab_free_hook mm/slub.c:1724 [inline]
 slab_free_freelist_hook+0x16c/0x1ec mm/slub.c:1750
 slab_free mm/slub.c:3661 [inline]
 __kmem_cache_free+0xc0/0x224 mm/slub.c:3674
 kfree+0xd0/0x1ac mm/slab_common.c:988
 release_mdev+0x20/0x30 drivers/most/most_usb.c:932
 device_release+0x8c/0x1ac drivers/base/core.c:-1
 kobject_cleanup lib/kobject.c:681 [inline]
 kobject_release lib/kobject.c:712 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x2b0/0x438 lib/kobject.c:729
 put_device drivers/base/core.c:3805 [inline]
 device_unregister+0x3c/0xcc drivers/base/core.c:3929
 most_deregister_interface+0x3e0/0x42c drivers/most/core.c:1402
 hdm_disconnect+0xdc/0x18c drivers/most/most_usb.c:1123
 usb_unbind_interface+0x1b8/0x750 drivers/usb/core/driver.c:458
 device_remove drivers/base/dd.c:550 [inline]
 __device_release_driver drivers/base/dd.c:1260 [inline]
 device_release_driver_internal+0x424/0x6d0 drivers/base/dd.c:1286
 device_release_driver+0x28/0x38 drivers/base/dd.c:1309
 bus_remove_device+0x294/0x388 drivers/base/bus.c:531
 device_del+0x568/0x96c drivers/base/core.c:3885
 usb_disable_device+0x33c/0x780 drivers/usb/core/message.c:1414
 usb_disconnect+0x284/0x790 drivers/usb/core/hub.c:2286
 hub_port_connect drivers/usb/core/hub.c:5333 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5629 [inline]
 port_event drivers/usb/core/hub.c:5785 [inline]
 hub_event+0x15e0/0x3dc4 drivers/usb/core/hub.c:5867
 process_one_work+0x7f4/0x13a8 kernel/workqueue.c:2292
 worker_thread+0x8c8/0xfbc kernel/workqueue.c:2439
 kthread+0x250/0x2d8 kernel/kthread.c:376
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:864

The buggy address belongs to the object at ffff0000d16a4000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 6320 bytes inside of
 8192-byte region [ffff0000d16a4000, ffff0000d16a6000)

The buggy address belongs to the physical page:
page:000000003df56988 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1116a0
head:000000003df56988 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x5ffc00000010200(slab|head|node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000010200 fffffc0003130800 dead000000000005 ffff0000c0002c00
raw: 0000000000000000 0000000000020002 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000d16a5780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff0000d16a5800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff0000d16a5880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff0000d16a5900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff0000d16a5980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 0 PID: 4701 at lib/refcount.c:28 refcount_warn_saturate+0x154/0x1f8 lib/refcount.c:28
Modules linked in:
CPU: 0 PID: 4701 Comm: kworker/0:11 Tainted: G    B              6.1.136-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: usb_hub_wq hub_event
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : refcount_warn_saturate+0x154/0x1f8 lib/refcount.c:28
lr : refcount_warn_saturate+0x154/0x1f8 lib/refcount.c:28
sp : ffff8000231a7400
x29: ffff8000231a7400 x28: ffff800017417aa0 x27: 1fffe0001a2d4800
x26: 1fffe0001a2d4807 x25: dfff800000000000 x24: ffff0000c44de030
x23: 1fffe0001a2d48a2 x22: ffff0000d16a403c x21: 0000000000000000
x20: ffff0000d16a4038 x19: ffff800017a32000 x18: ffff800011a7bd00
x17: 1fffe000367c2b76 x16: ffff800008042940 x15: 0000000040000000
x14: 0000000000000002 x13: 0000000000ff0100 x12: 0000000000ff0100
x11: ff00800008047bc4 x10: 0000000040000002 x9 : f50e2e5f68b05700
x8 : f50e2e5f68b05700 x7 : 0000000000000004 x6 : ffff8000082516e4
x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000000
x2 : ffff8000231a6fa0 x1 : 0000000000000000 x0 : ffff800008251778
Call trace:
 refcount_warn_saturate+0x154/0x1f8 lib/refcount.c:28
 __refcount_sub_and_test include/linux/refcount.h:283 [inline]
 __refcount_dec_and_test include/linux/refcount.h:315 [inline]
 refcount_dec_and_test include/linux/refcount.h:333 [inline]
 kref_put include/linux/kref.h:64 [inline]
 kobject_put+0x194/0x438 lib/kobject.c:729
 put_device+0x28/0x40 drivers/base/core.c:3805
 hdm_disconnect+0x174/0x18c drivers/most/most_usb.c:1130
 usb_unbind_interface+0x1b8/0x750 drivers/usb/core/driver.c:458
 device_remove drivers/base/dd.c:550 [inline]
 __device_release_driver drivers/base/dd.c:1260 [inline]
 device_release_driver_internal+0x424/0x6d0 drivers/base/dd.c:1286
 device_release_driver+0x28/0x38 drivers/base/dd.c:1309
 bus_remove_device+0x294/0x388 drivers/base/bus.c:531
 device_del+0x568/0x96c drivers/base/core.c:3885
 usb_disable_device+0x33c/0x780 drivers/usb/core/message.c:1414
 usb_disconnect+0x284/0x790 drivers/usb/core/hub.c:2286
 hub_port_connect drivers/usb/core/hub.c:5333 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5629 [inline]
 port_event drivers/usb/core/hub.c:5785 [inline]
 hub_event+0x15e0/0x3dc4 drivers/usb/core/hub.c:5867
 process_one_work+0x7f4/0x13a8 kernel/workqueue.c:2292
 worker_thread+0x8c8/0xfbc kernel/workqueue.c:2439
 kthread+0x250/0x2d8 kernel/kthread.c:376
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:864
irq event stamp: 9969
hardirqs last  enabled at (9969): [<ffff800008251778>] raw_spin_rq_unlock_irq kernel/sched/sched.h:1367 [inline]
hardirqs last  enabled at (9969): [<ffff800008251778>] finish_lock_switch+0xb0/0x1c4 kernel/sched/core.c:5003
hardirqs last disabled at (9968): [<ffff8000119eaaa4>] __schedule+0x298/0x1b2c kernel/sched/core.c:6459
softirqs last  enabled at (9494): [<ffff8000081a8dc0>] softirq_handle_end kernel/softirq.c:421 [inline]
softirqs last  enabled at (9494): [<ffff8000081a8dc0>] handle_softirqs+0xaf8/0xc6c kernel/softirq.c:606
softirqs last disabled at (9481): [<ffff800008020164>] __do_softirq+0x14/0x20 kernel/softirq.c:612
---[ end trace 0000000000000000 ]---