usb 2-1: USB disconnect, device number 8 ================================================================== BUG: KASAN: use-after-free in hdm_disconnect+0x109/0x1c0 drivers/most/most_usb.c:1125 Read of size 8 at addr ffff888019fe1960 by task kworker/1:10/4438 CPU: 1 PID: 4438 Comm: kworker/1:10 Not tainted 5.15.189-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: usb_hub_wq hub_event Call Trace: 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:2259 hub_port_connect drivers/usb/core/hub.c:5311 [inline] hub_port_connect_change drivers/usb/core/hub.c:5607 [inline] port_event drivers/usb/core/hub.c:5753 [inline] hub_event+0x1af8/0x4fa0 drivers/usb/core/hub.c:5835 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 Allocated by task 4438: 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:2604 hub_port_connect drivers/usb/core/hub.c:5467 [inline] hub_port_connect_change drivers/usb/core/hub.c:5607 [inline] port_event drivers/usb/core/hub.c:5753 [inline] hub_event+0x295c/0x4fa0 drivers/usb/core/hub.c:5835 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 4438: 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:1705 [inline] slab_free_freelist_hook+0xea/0x170 mm/slub.c:1731 slab_free mm/slub.c:3499 [inline] kfree+0xef/0x2a0 mm/slub.c:4559 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:2259 hub_port_connect drivers/usb/core/hub.c:5311 [inline] hub_port_connect_change drivers/usb/core/hub.c:5607 [inline] port_event drivers/usb/core/hub.c:5753 [inline] hub_event+0x1af8/0x4fa0 drivers/usb/core/hub.c:5835 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 ffff888019fe0000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 6496 bytes inside of 8192-byte region [ffff888019fe0000, ffff888019fe2000) The buggy address belongs to the page: page:ffffea000067f800 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x19fe0 head:ffffea000067f800 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 0000000100000001 ffff888016842280 raw: 0000000000000000 0000000000020002 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4191, ts 62320778150, free_ts 62268047468 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:5474 alloc_slab_page mm/slub.c:1775 [inline] allocate_slab mm/slub.c:1912 [inline] new_slab+0xc0/0x4b0 mm/slub.c:1975 ___slab_alloc+0x81e/0xdf0 mm/slub.c:3008 __slab_alloc mm/slub.c:3095 [inline] slab_alloc_node mm/slub.c:3186 [inline] slab_alloc mm/slub.c:3228 [inline] __kmalloc+0x1cd/0x330 mm/slub.c:4403 kmalloc_array include/linux/slab.h:644 [inline] kcalloc include/linux/slab.h:673 [inline] cache_create_net+0x8e/0x250 net/sunrpc/cache.c:1732 rsc_cache_create_net net/sunrpc/auth_gss/svcauth_gss.c:1948 [inline] gss_svc_init_net+0x54/0x410 net/sunrpc/auth_gss/svcauth_gss.c:1976 ops_init+0x357/0x600 net/core/net_namespace.c:138 setup_net+0x38d/0x9f0 net/core/net_namespace.c:333 copy_net_ns+0x348/0x5b0 net/core/net_namespace.c:503 create_new_namespaces+0x3d3/0x6f0 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x116/0x160 kernel/nsproxy.c:226 ksys_unshare+0x4bc/0x890 kernel/fork.c:3175 __do_sys_unshare kernel/fork.c:3249 [inline] __se_sys_unshare kernel/fork.c:3247 [inline] __x64_sys_unshare+0x34/0x40 kernel/fork.c:3247 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 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:2015 [inline] discard_slab mm/slub.c:2021 [inline] __unfreeze_partials+0x1a5/0x200 mm/slub.c:2507 put_cpu_partial+0x12d/0x190 mm/slub.c:2587 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:3220 [inline] slab_alloc mm/slub.c:3228 [inline] kmem_cache_alloc+0x100/0x290 mm/slub.c:3233 getname_flags+0xb5/0x500 fs/namei.c:138 do_sys_openat2+0xcf/0x4a0 fs/open.c:1247 do_sys_open fs/open.c:1269 [inline] __do_sys_openat fs/open.c:1285 [inline] __se_sys_openat fs/open.c:1280 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1280 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: ffff888019fe1800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888019fe1880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888019fe1900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888019fe1980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888019fe1a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================