In the Linux kernel, the following vulnerability has been resolved: staging: gdm724x: fix use after free in gdm_lte_rx() The netif_rx_ni() function frees the skb so we can't dereference it to save the skb->len.
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.