CVE-2023-53338

In the Linux kernel, the following vulnerability has been resolved: lwt: Fix return values of BPF xmit ops BPF encap ops can return different types of positive values, such like NET_RX_DROP, NET_XMIT_CN, NETDEV_TX_BUSY, and so on, from function skb_do_redirect and bpf_lwt_xmit_reroute. At the xmit hook, such return values would be treated implicitly as LWTUNNEL_XMIT_CONTINUE in ip(6)_finish_output2. When this happens, skbs that have been freed would continue to the neighbor subsystem, causing use-after-free bug and kernel crashes. To fix the incorrect behavior, skb_do_redirect return values can be simply discarded, the same as tc-egress behavior. On the other hand, bpf_lwt_xmit_reroute returns useful errors to local senders, e.g. PMTU information. Thus convert its return values to avoid the conflict with LWTUNNEL_XMIT_CONTINUE.

• linux linux kernel (>= 4.10 < 5.4.257) • linux linux kernel (>= 5.5 < 5.10.195) • linux linux kernel (>= 5.11 < 5.15.132) • linux linux kernel (>= 5.16 < 6.1.53) • linux linux kernel (>= 6.2 < 6.4.16) • linux linux kernel (>= 6.5 < 6.5.3)