CVE-2026-80824
Estado: RecibidaSin puntuar—
In the Linux kernel, the following vulnerability has been resolved:
usb: usbfs: fix use-after-free of usb_device in usbdev_release()
usbdev_release() drops its reference to the struct usb_device before draining the list of completed async URBs, but that drain path reads back through the same object: free_async() calls dec_usb_memory_use_count() for any URB whose buffer came from the usbfs mmap() region, and its first statement is bus_to_hcd(ps->dev->bus).
After a disconnect the usbfs reference can be the last one, in which case usb_put_dev() frees the device and the subsequent loop reads offset 80 of freed memory and uses the result as a struct usb_hcd *, which hcd_buffer_free_pages() then dereferences.
Leer descripción completaMostrar menos
This is reachable by an unprivileged process that has read/write access to a /dev/bus/usb node: mmap() the fd, submit one URB with a buffer inside the mapping, wait for the device to be unplugged, then munmap() and close(). It reproduces on every attempt rather than being a race, because a live MAP_SHARED vma holds a reference on the struct file, so usbdev_release() cannot run until the last vma is gone and the freeing branch of dec_usb_memory_use_count() is always taken.
Release the device reference after the drain loop instead. Nothing between the two points requires it to have been dropped.
Detalles técnicos trazas, registros y código del informe original
BUG: KASAN: slab-use-after-free in dec_usb_memory_use_count+0x3ae/0x410 Read of size 8 at addr ffff8880122ee050 by task poc/769 CPU: 1 UID: 1000 PID: 769 Comm: poc Tainted: G B 6.12.94 #3 Call Trace: dec_usb_memory_use_count+0x3ae/0x410 free_async+0x2aa/0x4f0 usbdev_release+0x375/0x460 __fput+0x3ea/0xb50 __x64_sys_close+0x86/0x100 Allocated by task 11: usb_alloc_dev+0x55/0xd90 hub_event+0x2524/0x43d0 Freed by task 769: kfree+0x121/0x360 device_release+0xd2/0x280 usb_put_dev+0x23/0x30 usbdev_release+0x2d8/0x460
CVSS
NVD no ha asignado puntuación CVSS a esta CVE (habitual desde el cambio de política de abril de 2026).
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.19%
- Percentil entre todas las CVEs puntuadas: 8
- Fecha de la puntuación: 6/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
Referencias
- https://git.kernel.org/stable/c/0a960b88c5979f853019d4dc4957dfbeeb193440
- https://git.kernel.org/stable/c/0dd68b5d01d022fc9c5e71c82a82b0a94d3d0671
- https://git.kernel.org/stable/c/47a7f98fbb5006d46d15a3a210ffdc61448a4f19
- https://git.kernel.org/stable/c/5f08c45bdcfd28d1171de38c5ef29fc89a76eedc
- https://git.kernel.org/stable/c/65879e0a452ca2a234b9475e0c11aff7a4343738
- https://git.kernel.org/stable/c/7f0278e474c4d1c4457974ff1137cc385c944ab3
- https://git.kernel.org/stable/c/96f5520fc9a5e4bbf77ac93c9d5ce502f597e6cf
- https://git.kernel.org/stable/c/b3cde26a66b04f1d90ed0b675899c88b4e49d424
- https://git.kernel.org/stable/c/bd4bffc621a8cb2f4d9ed9b6447415de524a3bef
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-80824",
"cveTags": [],
"metrics": {},
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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"published": "2026-09-04T16:18:10.233",
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{
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{
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"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nusb: usbfs: fix use-after-free of usb_device in usbdev_release()\n\nusbdev_release() drops its reference to the struct usb_device before\ndraining the list of completed async URBs, but that drain path reads back\nthrough the same object: free_async() calls dec_usb_memory_use_count()\nfor any URB whose buffer came from the usbfs mmap() region, and its first\nstatement is bus_to_hcd(ps->dev->bus).\n\nAfter a disconnect the usbfs reference can be the last one, in which case\nusb_put_dev() frees the device and the subsequent loop reads offset 80 of\nfreed memory and uses the result as a struct usb_hcd *, which\nhcd_buffer_free_pages() then dereferences.\n\nThis is reachable by an unprivileged process that has read/write access to\na /dev/bus/usb node: mmap() the fd, submit one URB with a buffer inside the\nmapping, wait for the device to be unplugged, then munmap() and close().\nIt reproduces on every attempt rather than being a race, because a live\nMAP_SHARED vma holds a reference on the struct file, so usbdev_release()\ncannot run until the last vma is gone and the freeing branch of\ndec_usb_memory_use_count() is always taken.\n\n BUG: KASAN: slab-use-after-free in dec_usb_memory_use_count+0x3ae/0x410\n Read of size 8 at addr ffff8880122ee050 by task poc/769\n CPU: 1 UID: 1000 PID: 769 Comm: poc Tainted: G B 6.12.94 #3\n\n Call Trace:\n dec_usb_memory_use_count+0x3ae/0x410\n free_async+0x2aa/0x4f0\n usbdev_release+0x375/0x460\n __fput+0x3ea/0xb50\n __x64_sys_close+0x86/0x100\n\n Allocated by task 11:\n usb_alloc_dev+0x55/0xd90\n hub_event+0x2524/0x43d0\n\n Freed by task 769:\n kfree+0x121/0x360\n device_release+0xd2/0x280\n usb_put_dev+0x23/0x30\n usbdev_release+0x2d8/0x460\n\nRelease the device reference after the drain loop instead. Nothing between\nthe two points requires it to have been dropped."
}
],
"lastModified": "2026-09-04T16:18:10.233",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}