CVE-2020-10751 – kernel: SELinux netlink permission check bypass

https://notcve.org/view.php?id=CVE-2020-10751

A flaw was found in the Linux kernels SELinux LSM hook implementation before version 5.7, where it incorrectly assumed that an skb would only contain a single netlink message. The hook would incorrectly only validate the first netlink message in the skb and allow or deny the rest of the messages within the skb with the granted permission without further processing. Se detectó un fallo en la implementación del enlace SELinux LSM de kernels de Linux versiones anteriores a 5.7, donde se asumía incorrectamente que un skb solo contendría un único mensaje netlink. El enlace incorrectamente solo comprobaría el primer mensaje netlink en el skb y permitiría o denegaría el resto de los mensajes dentro del skb con el permiso otorgado sin procesamiento adicional. A flaw was found in the Linux kernel’s SELinux LSM hook implementation, where it anticipated the skb would only contain a single Netlink message. • http://lists.opensuse.org/opensuse-security-announce/2020-06/msg00022.html http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00008.html http://www.openwall.com/lists/oss-security/2020/05/27/3 https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-10751 https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=fb73974172ffaaf57a7c42f35424d9aece1a5af6 https://lists.debian.org/debian-lts-announce/2020/06/msg00011.html https://lists.debian.org/debian-lts-announce • CWE-345: Insufficient Verification of Data Authenticity CWE-349: Acceptance of Extraneous Untrusted Data With Trusted Data •