Use After Free Bug in Linux Kernel's VXCan Interface

CVE-2021-47669

Summary

A use after free vulnerability exists in the Linux kernel's VXCan interface, specifically in the vxcan_xmit function. This flaw occurs after the netif_rx_ni(skb) call, where subsequent dereferencing of the skb pointer becomes unsafe. Notably, the canfd_frame cfd, which references the same skb memory, is accessed after it has been freed, potentially allowing an attacker to exploit this condition to disrupt normal operations or execute unwanted actions.

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