usb 5-1: SerialNumber: syz
usb 5-1: config 0 descriptor??
usb 5-1: USB disconnect, device number 7
==================================================================
BUG: KASAN: use-after-free in hdm_disconnect+0x109/0x1c0 drivers/most/most_usb.c:1125
Read of size 8 at addr ffff8880587dd960 by task kworker/1:4/4197

CPU: 1 PID: 4197 Comm: kworker/1:4 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: usb_hub_wq hub_event
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 print_address_description+0x60/0x2d0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0xdf/0x130 mm/kasan/report.c:451
 hdm_disconnect+0x109/0x1c0 drivers/most/most_usb.c:1125
 usb_unbind_interface+0x1ee/0x860 drivers/usb/core/driver.c:458
 __device_release_driver drivers/base/dd.c:1229 [inline]
 device_release_driver_internal+0x4b4/0x750 drivers/base/dd.c:1262
 bus_remove_device+0x2e2/0x400 drivers/base/bus.c:531
 device_del+0x628/0xa70 drivers/base/core.c:3600
 usb_disable_device+0x3e2/0x890 drivers/usb/core/message.c:1414
 usb_disconnect+0x348/0x8a0 drivers/usb/core/hub.c:2287
 hub_port_connect drivers/usb/core/hub.c:5341 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5637 [inline]
 port_event drivers/usb/core/hub.c:5799 [inline]
 hub_event+0x1e9f/0x5560 drivers/usb/core/hub.c:5881
 process_one_work+0x863/0x1000 kernel/workqueue.c:2310
 process_scheduled_works kernel/workqueue.c:2373 [inline]
 worker_thread+0xdca/0x12a0 kernel/workqueue.c:2459
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>

Allocated by task 4197:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 ____kasan_kmalloc mm/kasan/common.c:513 [inline]
 __kasan_kmalloc+0xb5/0xf0 mm/kasan/common.c:522
 kmalloc include/linux/slab.h:604 [inline]
 kzalloc include/linux/slab.h:735 [inline]
 hdm_probe+0x8f/0x13d0 drivers/most/most_usb.c:959
 usb_probe_interface+0x5a0/0xaf0 drivers/usb/core/driver.c:396
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x284/0xc80 drivers/base/dd.c:595
 __driver_probe_device+0x18c/0x330 drivers/base/dd.c:755
 driver_probe_device+0x4f/0x420 drivers/base/dd.c:785
 __device_attach_driver+0x2b0/0x500 drivers/base/dd.c:907
 bus_for_each_drv+0x175/0x200 drivers/base/bus.c:429
 __device_attach+0x29b/0x460 drivers/base/dd.c:979
 bus_probe_device+0xbc/0x1e0 drivers/base/bus.c:489
 device_add+0xa00/0xfb0 drivers/base/core.c:3412
 usb_set_configuration+0x1991/0x1fd0 drivers/usb/core/message.c:2165
 usb_generic_driver_probe+0x89/0x150 drivers/usb/core/generic.c:238
 usb_probe_device+0x139/0x270 drivers/usb/core/driver.c:293
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x284/0xc80 drivers/base/dd.c:595
 __driver_probe_device+0x18c/0x330 drivers/base/dd.c:755
 driver_probe_device+0x4f/0x420 drivers/base/dd.c:785
 __device_attach_driver+0x2b0/0x500 drivers/base/dd.c:907
 bus_for_each_drv+0x175/0x200 drivers/base/bus.c:429
 __device_attach+0x29b/0x460 drivers/base/dd.c:979
 bus_probe_device+0xbc/0x1e0 drivers/base/bus.c:489
 device_add+0xa00/0xfb0 drivers/base/core.c:3412
 usb_new_device+0xd53/0x1640 drivers/usb/core/hub.c:2632
 hub_port_connect drivers/usb/core/hub.c:5497 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5637 [inline]
 port_event drivers/usb/core/hub.c:5799 [inline]
 hub_event+0x2dd9/0x5560 drivers/usb/core/hub.c:5881
 process_one_work+0x863/0x1000 kernel/workqueue.c:2310
 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

Freed by task 4197:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:46
 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:1710 [inline]
 slab_free_freelist_hook+0xea/0x170 mm/slub.c:1736
 slab_free mm/slub.c:3504 [inline]
 kfree+0xef/0x2a0 mm/slub.c:4564
 device_release+0x92/0x1c0 drivers/base/core.c:-1
 kobject_cleanup lib/kobject.c:713 [inline]
 kobject_release lib/kobject.c:744 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x21d/0x460 lib/kobject.c:761
 hdm_disconnect+0xef/0x1c0 drivers/most/most_usb.c:1123
 usb_unbind_interface+0x1ee/0x860 drivers/usb/core/driver.c:458
 __device_release_driver drivers/base/dd.c:1229 [inline]
 device_release_driver_internal+0x4b4/0x750 drivers/base/dd.c:1262
 bus_remove_device+0x2e2/0x400 drivers/base/bus.c:531
 device_del+0x628/0xa70 drivers/base/core.c:3600
 usb_disable_device+0x3e2/0x890 drivers/usb/core/message.c:1414
 usb_disconnect+0x348/0x8a0 drivers/usb/core/hub.c:2287
 hub_port_connect drivers/usb/core/hub.c:5341 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5637 [inline]
 port_event drivers/usb/core/hub.c:5799 [inline]
 hub_event+0x1e9f/0x5560 drivers/usb/core/hub.c:5881
 process_one_work+0x863/0x1000 kernel/workqueue.c:2310
 process_scheduled_works kernel/workqueue.c:2373 [inline]
 worker_thread+0xdca/0x12a0 kernel/workqueue.c:2459
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

The buggy address belongs to the object at ffff8880587dc000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 6496 bytes inside of
 8192-byte region [ffff8880587dc000, ffff8880587de000)
The buggy address belongs to the page:
page:ffffea000161f600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x587d8
head:ffffea000161f600 order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 ffffea0001fd4800 0000000200000002 ffff888016842280
raw: 0000000000000000 0000000080020002 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 5054, ts 145234679668, free_ts 145178779952
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x1b77/0x1c60 mm/page_alloc.c:4192
 __alloc_pages+0x1e1/0x470 mm/page_alloc.c:5487
 alloc_slab_page mm/slub.c:1780 [inline]
 allocate_slab mm/slub.c:1917 [inline]
 new_slab+0xc0/0x4b0 mm/slub.c:1980
 ___slab_alloc+0x81e/0xdf0 mm/slub.c:3013
 __slab_alloc mm/slub.c:3100 [inline]
 slab_alloc_node mm/slub.c:3191 [inline]
 __kmalloc_node+0x200/0x3b0 mm/slub.c:4456
 kmalloc_node include/linux/slab.h:627 [inline]
 kvmalloc_node+0x84/0x130 mm/util.c:619
 kvmalloc include/linux/mm.h:816 [inline]
 kvzalloc include/linux/mm.h:824 [inline]
 snd_pcm_plugin_alloc+0x19c/0x780 sound/core/oss/pcm_plugin.c:74
 snd_pcm_plug_alloc+0x14a/0x270 sound/core/oss/pcm_plugin.c:133
 snd_pcm_oss_change_params_locked+0x281c/0x3e00 sound/core/oss/pcm_oss.c:1046
 snd_pcm_oss_change_params sound/core/oss/pcm_oss.c:1107 [inline]
 snd_pcm_oss_make_ready+0x11b/0x330 sound/core/oss/pcm_oss.c:1166
 snd_pcm_oss_sync+0x198/0xc00 sound/core/oss/pcm_oss.c:1733
 snd_pcm_oss_release+0xfe/0x240 sound/core/oss/pcm_oss.c:2587
 __fput+0x234/0x930 fs/file_table.c:311
 task_work_run+0x125/0x1a0 kernel/task_work.c:188
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1340 [inline]
 free_pcp_prepare mm/page_alloc.c:1391 [inline]
 free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317
 free_unref_page+0x94/0x280 mm/page_alloc.c:3396
 free_slab mm/slub.c:2020 [inline]
 discard_slab mm/slub.c:2026 [inline]
 __unfreeze_partials+0x1a5/0x200 mm/slub.c:2512
 put_cpu_partial+0x12d/0x190 mm/slub.c:2592
 qlist_free_all+0x35/0x90 mm/kasan/quarantine.c:176
 kasan_quarantine_reduce+0x150/0x160 mm/kasan/quarantine.c:283
 __kasan_slab_alloc+0x2f/0xd0 mm/kasan/common.c:444
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519
 slab_alloc_node mm/slub.c:3225 [inline]
 slab_alloc mm/slub.c:3233 [inline]
 kmem_cache_alloc+0x100/0x290 mm/slub.c:3238
 getname_flags+0xb5/0x500 fs/namei.c:138
 user_path_at_empty+0x2a/0x190 fs/namei.c:2882
 user_path_at include/linux/namei.h:57 [inline]
 __do_sys_chdir fs/open.c:490 [inline]
 __se_sys_chdir+0x91/0x280 fs/open.c:484
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

Memory state around the buggy address:
 ffff8880587dd800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880587dd880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880587dd900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                       ^
 ffff8880587dd980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880587dda00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================