The Linux kernel vulnerability (CVE-2026-80977) arises from skb_tx_error() improperly modifying shared zerocopy state flags in skb_shinfo(), which is shared among skb clones. This results in signaling that pages are free and dropping SKBFL_SHARED_FRAG for skbs still in flight, potentially causing data corruption or incorrect processing in subsystems like Open vSwitch and ESP packet handling. The issue is triggered when a cloned skb is processed without privatizing fragments, leading to a flow miss that strips markers from the original packet still being forwarded. The resolution is to skip zerocopy state handling for cloned skbs, ensuring skb_release_data() clears the state only when the last reference is dropped.

This vulnerability can lead to incorrect handling of network packet fragments, potentially causing data corruption or improper packet processing in kernel networking components such as Open vSwitch and ESP decryption. There is no indication of remote code execution or privilege escalation. No known exploits in the wild have been reported.

A fix has been implemented in the Linux kernel to skip zerocopy state modifications for cloned skbs, preventing premature clearing of shared state. Users should apply the official kernel updates that include this fix. Since this is a kernel-level vulnerability, updating to the patched kernel version is the recommended remediation. Patch status is not explicitly stated in the provided data; users should consult the vendor or kernel mailing list advisories for the exact fixed versions.