em28xx 9-1:0.0: AC97 chip type couldn't be determined em28xx 9-1:0.0: No AC97 audio processor usb 9-1: USB disconnect, device number 16 em28xx 9-1:0.0: Disconnecting em28xx ================================================================== BUG: KFENCE: use-after-free read in media_devnode_unregister+0x92/0xf0 drivers/media/mc/mc-devnode.c:284 Use-after-free read at 0xffff88823bffacf0 (in kfence-#252): media_devnode_unregister+0x92/0xf0 drivers/media/mc/mc-devnode.c:284 media_device_unregister+0x37c/0x400 drivers/media/mc/mc-device.c:828 em28xx_unregister_media_device drivers/media/usb/em28xx/em28xx-cards.c:3511 [inline] em28xx_release_resources+0xac/0x240 drivers/media/usb/em28xx/em28xx-cards.c:3532 em28xx_usb_disconnect+0x19f/0x2f0 drivers/media/usb/em28xx/em28xx-cards.c:4201 usb_unbind_interface+0x26e/0x910 drivers/usb/core/driver.c:458 device_remove drivers/base/dd.c:571 [inline] __device_release_driver drivers/base/dd.c:1274 [inline] device_release_driver_internal+0x4d9/0x800 drivers/base/dd.c:1297 bus_remove_device+0x34d/0x410 drivers/base/bus.c:579 device_del+0x511/0x8e0 drivers/base/core.c:3878 usb_disable_device+0x3e9/0x8a0 drivers/usb/core/message.c:1418 usb_disconnect+0x330/0x950 drivers/usb/core/hub.c:2344 hub_port_connect drivers/usb/core/hub.c:5406 [inline] hub_port_connect_change drivers/usb/core/hub.c:5706 [inline] port_event drivers/usb/core/hub.c:5870 [inline] hub_event+0x1cf5/0x4a20 drivers/usb/core/hub.c:5952 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x47c/0x820 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 kfence-#252: 0xffff88823bffa800-0xffff88823bffad07, size=1288, cache=kmalloc-2k allocated by task 19266 on cpu 0 at 1657.594348s (0.149321s ago): kmalloc_noprof include/linux/slab.h:956 [inline] kzalloc_noprof include/linux/slab.h:1090 [inline] __media_device_register+0x58/0x280 drivers/media/mc/mc-device.c:720 em28xx_usb_probe+0x1764/0x2a20 drivers/media/usb/em28xx/em28xx-cards.c:4153 usb_probe_interface+0x665/0xc30 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x26d/0x9e0 drivers/base/dd.c:659 __driver_probe_device+0x18c/0x2f0 drivers/base/dd.c:801 driver_probe_device+0x4f/0x430 drivers/base/dd.c:831 __device_attach_driver+0x2ce/0x530 drivers/base/dd.c:959 bus_for_each_drv+0x24e/0x2e0 drivers/base/bus.c:462 __device_attach+0x2b8/0x400 drivers/base/dd.c:1031 bus_probe_device+0x185/0x260 drivers/base/bus.c:537 device_add+0x7b6/0xb50 drivers/base/core.c:3689 usb_set_configuration+0x1a87/0x20e0 drivers/usb/core/message.c:2210 usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:250 usb_probe_device+0x1c1/0x390 drivers/usb/core/driver.c:291 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x26d/0x9e0 drivers/base/dd.c:659 __driver_probe_device+0x18c/0x2f0 drivers/base/dd.c:801 driver_probe_device+0x4f/0x430 drivers/base/dd.c:831 __device_attach_driver+0x2ce/0x530 drivers/base/dd.c:959 bus_for_each_drv+0x24e/0x2e0 drivers/base/bus.c:462 __device_attach+0x2b8/0x400 drivers/base/dd.c:1031 bus_probe_device+0x185/0x260 drivers/base/bus.c:537 device_add+0x7b6/0xb50 drivers/base/core.c:3689 usb_new_device+0xa39/0x16f0 drivers/usb/core/hub.c:2694 hub_port_connect drivers/usb/core/hub.c:5566 [inline] hub_port_connect_change drivers/usb/core/hub.c:5706 [inline] port_event drivers/usb/core/hub.c:5870 [inline] hub_event+0x2958/0x4a20 drivers/usb/core/hub.c:5952 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x47c/0x820 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 freed by task 19266 on cpu 0 at 1657.623501s (0.272686s ago): media_devnode_release+0x61/0xa0 drivers/media/mc/mc-devnode.c:57 device_release+0x99/0x1c0 drivers/base/core.c:-1 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x228/0x480 lib/kobject.c:737 media_devnode_unregister+0x6d/0xf0 drivers/media/mc/mc-devnode.c:281 media_device_unregister+0x37c/0x400 drivers/media/mc/mc-device.c:828 em28xx_unregister_media_device drivers/media/usb/em28xx/em28xx-cards.c:3511 [inline] em28xx_release_resources+0xac/0x240 drivers/media/usb/em28xx/em28xx-cards.c:3532 em28xx_usb_disconnect+0x19f/0x2f0 drivers/media/usb/em28xx/em28xx-cards.c:4201 usb_unbind_interface+0x26e/0x910 drivers/usb/core/driver.c:458 device_remove drivers/base/dd.c:571 [inline] __device_release_driver drivers/base/dd.c:1274 [inline] device_release_driver_internal+0x4d9/0x800 drivers/base/dd.c:1297 bus_remove_device+0x34d/0x410 drivers/base/bus.c:579 device_del+0x511/0x8e0 drivers/base/core.c:3878 usb_disable_device+0x3e9/0x8a0 drivers/usb/core/message.c:1418 usb_disconnect+0x330/0x950 drivers/usb/core/hub.c:2344 hub_port_connect drivers/usb/core/hub.c:5406 [inline] hub_port_connect_change drivers/usb/core/hub.c:5706 [inline] port_event drivers/usb/core/hub.c:5870 [inline] hub_event+0x1cf5/0x4a20 drivers/usb/core/hub.c:5952 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x47c/0x820 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 CPU: 0 UID: 0 PID: 19266 Comm: kworker/0:2 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: usb_hub_wq hub_event RIP: 0010:media_devnode_unregister+0x92/0xf0 drivers/media/mc/mc-devnode.c:284 Code: e8 93 d6 38 fe 48 c7 c7 40 1a 20 8f 31 f6 e8 f5 16 b9 03 48 81 c3 f0 04 00 00 48 89 d8 48 c1 e8 03 42 0f b6 04 38 84 c0 75 3c <48> 63 1b 8d 43 3f 85 db 0f 49 c3 c1 f8 06 48 98 48 8d 3c c5 c0 51 RSP: 0018:ffffc90003387328 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff88823bffacf0 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8c0361e0 RDI: 00000000ffffffff RBP: 1ffff1100488abee R08: ffffffff8fc3ce37 R09: 1ffffffff1f879c6 R10: dffffc0000000000 R11: fffffbfff1f879c7 R12: ffff888055ee1918 R13: ffff888055ee1918 R14: ffff88823bffa810 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8881259f0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff88823bffacf0 CR3: 0000000082ff4000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000002020 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: media_device_unregister+0x37c/0x400 drivers/media/mc/mc-device.c:828 em28xx_unregister_media_device drivers/media/usb/em28xx/em28xx-cards.c:3511 [inline] em28xx_release_resources+0xac/0x240 drivers/media/usb/em28xx/em28xx-cards.c:3532 em28xx_usb_disconnect+0x19f/0x2f0 drivers/media/usb/em28xx/em28xx-cards.c:4201 usb_unbind_interface+0x26e/0x910 drivers/usb/core/driver.c:458 device_remove drivers/base/dd.c:571 [inline] __device_release_driver drivers/base/dd.c:1274 [inline] device_release_driver_internal+0x4d9/0x800 drivers/base/dd.c:1297 bus_remove_device+0x34d/0x410 drivers/base/bus.c:579 device_del+0x511/0x8e0 drivers/base/core.c:3878 usb_disable_device+0x3e9/0x8a0 drivers/usb/core/message.c:1418 usb_disconnect+0x330/0x950 drivers/usb/core/hub.c:2344 hub_port_connect drivers/usb/core/hub.c:5406 [inline] hub_port_connect_change drivers/usb/core/hub.c:5706 [inline] port_event drivers/usb/core/hub.c:5870 [inline] hub_event+0x1cf5/0x4a20 drivers/usb/core/hub.c:5952 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x47c/0x820 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 ================================================================== ---------------- Code disassembly (best guess): 0: e8 93 d6 38 fe call 0xfe38d698 5: 48 c7 c7 40 1a 20 8f mov $0xffffffff8f201a40,%rdi c: 31 f6 xor %esi,%esi e: e8 f5 16 b9 03 call 0x3b91708 13: 48 81 c3 f0 04 00 00 add $0x4f0,%rbx 1a: 48 89 d8 mov %rbx,%rax 1d: 48 c1 e8 03 shr $0x3,%rax 21: 42 0f b6 04 38 movzbl (%rax,%r15,1),%eax 26: 84 c0 test %al,%al 28: 75 3c jne 0x66 * 2a: 48 63 1b movslq (%rbx),%rbx <-- trapping instruction 2d: 8d 43 3f lea 0x3f(%rbx),%eax 30: 85 db test %ebx,%ebx 32: 0f 49 c3 cmovns %ebx,%eax 35: c1 f8 06 sar $0x6,%eax 38: 48 98 cltq 3a: 48 rex.W 3b: 8d .byte 0x8d 3c: 3c c5 cmp $0xc5,%al 3e: c0 .byte 0xc0 3f: 51 push %rcx