CVE-2022-50253: 
Linux Kernel vulnerability analysis and mitigation

A vulnerability in the Linux kernel's BPF (Berkeley Packet Filter) subsystem was identified as CVE-2022-50253. The issue occurs when redirecting packets to a tunneling device, where a case was discovered where skb->len could be 0 when entering __dev_queue_xmit. This vulnerability was reported through the syzkaller testing environment and was disclosed on September 15, 2025 (NVD).

The vulnerability manifests when a correctly sized ETH_HLEN packet is generated and redirected to a tunneling device. The issue arises after __skb_pull is called on the L2 header, which can result in skb->len becoming 0. The problem was identified through a warning triggered at include/linux/skbuff.h:2576 in the skb_assert_len function. The vulnerability affects the BPF subsystem's packet handling mechanisms, particularly in the context of tunnel redirection (NVD).

When exploited, this vulnerability could potentially lead to system warnings and improper packet handling in the Linux kernel's networking stack. The issue specifically affects the packet processing pipeline when dealing with tunneled network traffic (NVD).

The suggested fix involves implementing an explicit check after __skb_pull to ensure skb->len is not 0 when redirecting to a tunneling device. Multiple kernel patches have been developed to address this issue, as evidenced by the various commit references in the kernel repository (NVD).