usb 4-1: USB disconnect, device number 2 ================================================================== BUG: KASAN: use-after-free in __media_entity_remove_links+0x120/0x150 drivers/media/mc/mc-entity.c:779 Read of size 8 at addr ffff888097ac1820 by task kworker/0:28/2859 CPU: 0 PID: 2859 Comm: kworker/0:28 Not tainted 5.6.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: usb_hub_wq hub_event Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x128/0x182 lib/dump_stack.c:118 print_address_description.constprop.8.cold.10+0x9/0x317 mm/kasan/report.c:374 __kasan_report.cold.11+0x1c/0x34 mm/kasan/report.c:506 kasan_report+0xe/0x20 mm/kasan/common.c:641 __media_entity_remove_links+0x120/0x150 drivers/media/mc/mc-entity.c:779 __media_device_unregister_entity+0x161/0x2a0 drivers/media/mc/mc-device.c:596 media_device_unregister_entity+0x3e/0x60 drivers/media/mc/mc-device.c:688 v4l2_device_unregister_subdev+0x211/0x330 drivers/media/v4l2-core/v4l2-device.c:283 v4l2_device_unregister+0xf5/0x1c0 drivers/media/v4l2-core/v4l2-device.c:100 uvc_unregister_video+0xe7/0x1b0 drivers/media/usb/uvc/uvc_driver.c:1957 uvc_disconnect+0x98/0x100 drivers/media/usb/uvc/uvc_driver.c:2270 usb_unbind_interface+0x15c/0x870 drivers/usb/core/driver.c:423 __device_release_driver drivers/base/dd.c:1137 [inline] device_release_driver_internal+0x1d2/0x470 drivers/base/dd.c:1168 bus_remove_device+0x293/0x460 drivers/base/bus.c:533 device_del+0x421/0xc00 drivers/base/core.c:2677 usb_disable_device+0x1ae/0x580 drivers/usb/core/message.c:1237 usb_disconnect+0x227/0x850 drivers/usb/core/hub.c:2211 hub_port_connect drivers/usb/core/hub.c:5046 [inline] hub_port_connect_change drivers/usb/core/hub.c:5335 [inline] port_event drivers/usb/core/hub.c:5481 [inline] hub_event+0x1048/0x2d60 drivers/usb/core/hub.c:5563 process_one_work+0x903/0x15c0 kernel/workqueue.c:2264 worker_thread+0x82/0xb50 kernel/workqueue.c:2410 kthread+0x31d/0x3e0 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Allocated by task 3103: save_stack+0x19/0x80 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] __kasan_kmalloc.constprop.17+0xc1/0xd0 mm/kasan/common.c:515 kmem_cache_alloc_trace+0x156/0x780 mm/slab.c:3551 kmalloc include/linux/slab.h:555 [inline] kzalloc include/linux/slab.h:669 [inline] media_add_link+0x43/0x150 drivers/media/mc/mc-entity.c:592 media_create_pad_link+0x1b6/0x590 drivers/media/mc/mc-entity.c:684 uvc_mc_create_links drivers/media/usb/uvc/uvc_entity.c:50 [inline] uvc_mc_register_entities+0x3fc/0x706 drivers/media/usb/uvc/uvc_entity.c:114 uvc_register_chains drivers/media/usb/uvc/uvc_driver.c:2103 [inline] uvc_probe.cold.19+0x186a/0x292c drivers/media/usb/uvc/uvc_driver.c:2229 usb_probe_interface+0x268/0x6c0 drivers/usb/core/driver.c:361 really_probe+0x1f9/0x5e0 drivers/base/dd.c:551 driver_probe_device+0xc9/0x1b0 drivers/base/dd.c:724 bus_for_each_drv+0x117/0x1a0 drivers/base/bus.c:431 __device_attach+0x1be/0x2c0 drivers/base/dd.c:897 bus_probe_device+0x19e/0x250 drivers/base/bus.c:491 device_add+0x10d0/0x1900 drivers/base/core.c:2500 usb_set_configuration+0xc02/0x1560 drivers/usb/core/message.c:2023 generic_probe+0x61/0x8a drivers/usb/core/generic.c:210 really_probe+0x1f9/0x5e0 drivers/base/dd.c:551 driver_probe_device+0xc9/0x1b0 drivers/base/dd.c:724 bus_for_each_drv+0x117/0x1a0 drivers/base/bus.c:431 __device_attach+0x1be/0x2c0 drivers/base/dd.c:897 bus_probe_device+0x19e/0x250 drivers/base/bus.c:491 device_add+0x10d0/0x1900 drivers/base/core.c:2500 usb_new_device.cold.66+0x679/0xe85 drivers/usb/core/hub.c:2548 hub_port_connect drivers/usb/core/hub.c:5195 [inline] hub_port_connect_change drivers/usb/core/hub.c:5335 [inline] port_event drivers/usb/core/hub.c:5481 [inline] hub_event+0x15fe/0x2d60 drivers/usb/core/hub.c:5563 process_one_work+0x903/0x15c0 kernel/workqueue.c:2264 worker_thread+0x82/0xb50 kernel/workqueue.c:2410 kthread+0x31d/0x3e0 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Freed by task 2859: save_stack+0x19/0x80 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+0xf7/0x140 mm/kasan/common.c:476 __cache_free mm/slab.c:3426 [inline] kfree+0x107/0x2b0 mm/slab.c:3757 __media_entity_remove_link+0x22a/0x5e0 drivers/media/mc/mc-entity.c:622 __media_entity_remove_links+0x75/0x150 drivers/media/mc/mc-entity.c:780 __media_device_unregister_entity+0x161/0x2a0 drivers/media/mc/mc-device.c:596 media_device_unregister_entity+0x3e/0x60 drivers/media/mc/mc-device.c:688 v4l2_device_unregister_subdev+0x211/0x330 drivers/media/v4l2-core/v4l2-device.c:283 v4l2_device_unregister+0xf5/0x1c0 drivers/media/v4l2-core/v4l2-device.c:100 uvc_unregister_video+0xe7/0x1b0 drivers/media/usb/uvc/uvc_driver.c:1957 uvc_disconnect+0x98/0x100 drivers/media/usb/uvc/uvc_driver.c:2270 usb_unbind_interface+0x15c/0x870 drivers/usb/core/driver.c:423 __device_release_driver drivers/base/dd.c:1137 [inline] device_release_driver_internal+0x1d2/0x470 drivers/base/dd.c:1168 bus_remove_device+0x293/0x460 drivers/base/bus.c:533 device_del+0x421/0xc00 drivers/base/core.c:2677 usb_disable_device+0x1ae/0x580 drivers/usb/core/message.c:1237 usb_disconnect+0x227/0x850 drivers/usb/core/hub.c:2211 hub_port_connect drivers/usb/core/hub.c:5046 [inline] hub_port_connect_change drivers/usb/core/hub.c:5335 [inline] port_event drivers/usb/core/hub.c:5481 [inline] hub_event+0x1048/0x2d60 drivers/usb/core/hub.c:5563 process_one_work+0x903/0x15c0 kernel/workqueue.c:2264 worker_thread+0x82/0xb50 kernel/workqueue.c:2410 kthread+0x31d/0x3e0 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 The buggy address belongs to the object at ffff888097ac1800 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 32 bytes inside of 96-byte region [ffff888097ac1800, ffff888097ac1860) The buggy address belongs to the page: page:ffffea00025eb040 refcount:1 mapcount:0 mapping:ffff8880aa400540 index:0x0 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea00024b0288 ffffea00023a8e48 ffff8880aa400540 raw: 0000000000000000 ffff888097ac1000 0000000100000020 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888097ac1700: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc ffff888097ac1780: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc >ffff888097ac1800: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff888097ac1880: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff888097ac1900: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc ==================================================================