CVE-2026-98025

CVE-2026-98025 · net: usb: cx82310_eth: drop URB after 0xffff reboot sentinel to prevent partial_data heap overflow

Esta página presenta datos de fuentes públicas de vulnerabilidades. Consulta el aviso original antes de actualizar.

Esta página muestra una selección de datos de las fuentes. Consulte los avisos enlazados para ver la descripción completa y las versiones afectadas.

In the Linux kernel, the following vulnerability has been resolved: net: usb: cx82310_eth: drop URB after 0xffff reboot sentinel to prevent partial_data heap overflow The 0xffff length sentinel detects a router reboot and schedules re-enabling of ethernet mode, but then falls through to the rest of the loop body. The next check is } else if (len > CX82310_MTU) { which is the else of the just-matched if -- it never fires for len == 0xffff. The MTU bound that normally caps the incomplete-packet save path is silently bypassed. With 0xffff > skb->len always true (rx_urb_size is 4096), the incomplete-packet branch saves dev->partial_len = skb->len bytes into dev->partial_data. partial_data is kmalloc(hard_mtu) = kmalloc(CX82310_MTU + 2) = 1516 bytes, but skb->len after the 2-byte header pull can be up to 4094. A device that sends a 4096-byte URB starting with [0xff 0xff] therefore copies 4094 device-provided bytes into a buffer allocated for 1516 bytes, exceeding its requested size by 2578 bytes. The next URB then reads dev->partial_len (4094) back from the same 1516-byte buffer and dev->partial_rem (65535 - 4094 = 61441) from the new URB's ~4KB skb, both well past their allocations, and delivers the spliced result as a 64KB "frame" to the network stack. Bail out of rx_fixup after scheduling the re-enable work; the remainder of a reboot-marker URB is not meaningful packet data. This restores the invariant that partial_len < CX82310_MTU + 2 on the save path, since every other route there has already passed the MTU check.

EPSS 0,2% · Corrección disponible

Publicación

2026-09-25T10:23:43.906Z

Actualización

2026-10-19T09:12:30.354Z

Pila tecnológica: system

Comprueba tu servidor →