In the Linux kernel, the following vulnerability has been resolved: mlx5: fix possible ptp queue fifo use-after-free Fifo indexes are not checked during pop operations and it leads to potential use-after-free when poping from empty queue. Such case was possible during re-sync action. WARN_ON_ONCE covers future cases. There were out-of-order cqe spotted which lead to drain of the queue and use-after-free because of lack of fifo pointers check. Special check and counter are added to avoid resync operation if SKB could not exist in the fifo because of OOO cqe (skb_id must be between consumer and producer index).