em28xx 7-1:0.132: Closing input extension ================================================================== BUG: KASAN: slab-use-after-free in media_device_unregister drivers/media/mc/mc-device.c:833 [inline] BUG: KASAN: slab-use-after-free in media_device_unregister+0x59d/0x610 drivers/media/mc/mc-device.c:811 Read of size 8 at addr ffff88813325c218 by task kworker/1:6/5389 CPU: 1 UID: 0 PID: 5389 Comm: kworker/1:6 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: usb_hub_wq hub_event Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x156/0x4c9 mm/kasan/report.c:482 kasan_report+0xdf/0x1e0 mm/kasan/report.c:595 media_device_unregister drivers/media/mc/mc-device.c:833 [inline] media_device_unregister+0x59d/0x610 drivers/media/mc/mc-device.c:811 em28xx_unregister_media_device+0x4e/0xe0 drivers/media/usb/em28xx/em28xx-cards.c:3511 em28xx_release_resources+0x79/0x1b0 drivers/media/usb/em28xx/em28xx-cards.c:3532 em28xx_usb_disconnect.cold+0x17d/0x253 drivers/media/usb/em28xx/em28xx-cards.c:4201 usb_unbind_interface+0x1dd/0x9e0 drivers/usb/core/driver.c:458 device_remove drivers/base/dd.c:573 [inline] device_remove+0x12a/0x180 drivers/base/dd.c:565 __device_release_driver drivers/base/dd.c:1284 [inline] device_release_driver_internal+0x42e/0x600 drivers/base/dd.c:1307 bus_remove_device+0x22f/0x440 drivers/base/bus.c:616 device_del+0x376/0x9b0 drivers/base/core.c:3878 usb_disable_device+0x367/0x810 drivers/usb/core/message.c:1478 usb_disconnect+0x2e2/0x9a0 drivers/usb/core/hub.c:2345 hub_port_connect drivers/usb/core/hub.c:5407 [inline] hub_port_connect_change drivers/usb/core/hub.c:5707 [inline] port_event drivers/usb/core/hub.c:5871 [inline] hub_event+0x1d0c/0x4af0 drivers/usb/core/hub.c:5953 process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276 process_scheduled_works kernel/workqueue.c:3359 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x6c3/0xcb0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 23: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:415 kmalloc_noprof include/linux/slab.h:950 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] em28xx_v4l2_init.cold+0x94/0x3503 drivers/media/usb/em28xx/em28xx-video.c:2532 em28xx_init_extension+0x13a/0x200 drivers/media/usb/em28xx/em28xx-core.c:1117 request_module_async+0x61/0x80 drivers/media/usb/em28xx/em28xx-cards.c:3457 process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276 process_scheduled_works kernel/workqueue.c:3359 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x6c3/0xcb0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 23: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x43/0x70 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2685 [inline] slab_free mm/slub.c:6165 [inline] kfree+0x1dc/0x640 mm/slub.c:6483 kref_put.isra.0+0x56/0x90 include/linux/kref.h:65 em28xx_v4l2_init.cold+0x280/0x3503 drivers/media/usb/em28xx/em28xx-video.c:2901 em28xx_init_extension+0x13a/0x200 drivers/media/usb/em28xx/em28xx-core.c:1117 request_module_async+0x61/0x80 drivers/media/usb/em28xx/em28xx-cards.c:3457 process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276 process_scheduled_works kernel/workqueue.c:3359 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x6c3/0xcb0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 The buggy address belongs to the object at ffff88813325c000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 536 bytes inside of freed 8192-byte region [ffff88813325c000, ffff88813325e000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x133258 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x200000000000040(head|node=0|zone=2) page_type: f5(slab) raw: 0200000000000040 ffff888100042280 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800020002 00000000f5000000 0000000000000000 head: 0200000000000040 ffff888100042280 dead000000000100 dead000000000122 head: 0000000000000000 0000000800020002 00000000f5000000 0000000000000000 head: 0200000000000003 ffffea0004cc9601 00000000ffffffff 00000000ffffffff head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000008 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 2969, tgid 2969 (syz-executor), ts 46493084202, free_ts 0 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x153/0x170 mm/page_alloc.c:1889 prep_new_page mm/page_alloc.c:1897 [inline] get_page_from_freelist+0xf10/0x39f0 mm/page_alloc.c:3962 __alloc_frozen_pages_noprof+0x273/0x2860 mm/page_alloc.c:5250 alloc_slab_page mm/slub.c:3292 [inline] allocate_slab mm/slub.c:3481 [inline] new_slab+0xa6/0x6c0 mm/slub.c:3539 refill_objects+0x26b/0x400 mm/slub.c:7175 refill_sheaf mm/slub.c:2812 [inline] __pcs_replace_empty_main+0x1ab/0x660 mm/slub.c:4615 alloc_from_pcs mm/slub.c:4717 [inline] slab_alloc_node mm/slub.c:4851 [inline] __do_kmalloc_node mm/slub.c:5259 [inline] __kmalloc_noprof+0x645/0x810 mm/slub.c:5272 kmalloc_noprof include/linux/slab.h:954 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] cache_create_net+0xa2/0x1f0 net/sunrpc/cache.c:1748 rsc_cache_create_net net/sunrpc/auth_gss/svcauth_gss.c:2054 [inline] gss_svc_init_net+0x69/0x640 net/sunrpc/auth_gss/svcauth_gss.c:2082 ops_init+0x1e2/0x5f0 net/core/net_namespace.c:137 setup_net+0x118/0x3a0 net/core/net_namespace.c:446 copy_net_ns+0x440/0x780 net/core/net_namespace.c:581 create_new_namespaces+0x3ea/0xc00 kernel/nsproxy.c:130 unshare_nsproxy_namespaces+0xc3/0x1f0 kernel/nsproxy.c:226 ksys_unshare+0x473/0xad0 kernel/fork.c:3173 __do_sys_unshare kernel/fork.c:3244 [inline] __se_sys_unshare kernel/fork.c:3242 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:3242 page_owner free stack trace missing Memory state around the buggy address: ffff88813325c100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88813325c180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88813325c200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88813325c280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88813325c300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================