CVE-2021-47301

En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: igb: corrige el error de use after free durante el reinicio. Limpia el siguiente descriptor a observar (next_to_watch) al limpiar el anillo TX. De lo contrario, se pueden producir accesos a la memoria no válidos. Si igb_poll() se ejecuta mientras se reinicia el controlador, esto puede hacer que el controlador intente liberar un skb que ya estaba liberado. (El fallo es más difícil de reproducir con el controlador igb, pero existe el mismo problema potencial ya que el código es idéntico al de igc)

A vulnerability was found in the Linux kernel's igb driver. During a reset operation, the driver could access memory that had already been freed. If the driver attempts to use this freed memory, it can lead to a system crash or instability because the memory may no longer be valid.

In the Linux kernel, the following vulnerability has been resolved: igb: Fix use-after-free error during reset Cleans the next descriptor to watch (next_to_watch) when cleaning the TX ring. Failure to do so can cause invalid memory accesses. If igb_poll() runs while the controller is reset this can lead to the driver try to free a skb that was already freed. (The crash is harder to reproduce with the igb driver, but the same potential problem exists as the code is identical to igc)