The Linux kernel had a conflict between the Private Socket Protocol (PSP) and TLS User-Defined Protocol Layer (TLS ULP) in their use of shared state variables: the skb->decrypted flag and the sk_validate_xmit_skb() pointer. Because these components were not mutually exclusive, the kernel could incorrectly validate packets when both PSP and TLS ULP were present. The change makes PSP mutually exclusive with TLS ULP, ensures proper initialization of these state variables, and closes off surface area that might otherwise expose bugs.

This issue impacts all Linux kernel users that are running a kernel build prior to the commit that introduces PSP/TLS ULP conflict remediation. Versions of the kernel compiled with PSP support and TLS ULP enabled are affected, regardless of distribution or kernel variant.

The EPSS score of <1% indicates a very low likelihood of exploitation, and the vulnerability is not listed in the CISA KEV catalog. The flaw involves shared state used during packet validation between PSP and TLS ULP. Based on the description, it is inferred that an attacker who can send crafted network traffic to a socket that has both PSP and TLS ULP enabled might be able to trigger a misvalidation or crash, implying a possible network-based attack vector. While no exploit has been documented, the low exploitation probability and absence of public vulnerability reports suggest the overall risk remains low, although applying the patch removes the potential for incorrect packet handling.