CVE-2023-53836 — Improper Update of Reference Count in Linux

In the Linux kernel, the following vulnerability has been resolved: bpf, sockmap: Fix skb refcnt race after locking changes There is a race where skb's from the sk_psock_backlog can be referenced after userspace side has already skb_consumed() the sk_buff and its refcnt dropped to zer0 causing use after free. The flow is the following: while ((skb = skb_peek(&psock->ingress_skb)) sk_psock_handle_Skb(psock, skb, ..., ingress) if (!ingress) ... sk_psock_skb_ingress sk_psock_skb_ingress_enqueue…