CVE-2014-5045

La función mountpoint_last en fs/namei.c en el kernel de Linux anterior a 3.15.8 no mantiene debidamente cierta cuenta de referencias durante intentos de utilizar la llamada al sistema umount en conjunto con un enlace simbólico, lo que permite a usuarios locales causar una denegación de servicio (consumo de memoria o uso después de liberación) o posiblemente tener otro impacto no especificado a través del programa umount.

A flaw was found in the way the Linux kernel's VFS subsystem handled reference counting when performing unmount operations on symbolic links. A local, unprivileged user could use this flaw to exhaust all available memory on the system or, potentially, trigger a use-after-free error, resulting in a system crash or privilege escalation.

The kernel packages contain the Linux kernel, the core of any Linux operating system. A NULL pointer dereference flaw was found in the way the Linux kernel's Stream Control Transmission Protocol implementation handled simultaneous connections between the same hosts. A remote attacker could use this flaw to crash the system. An integer overflow flaw was found in the way the Linux kernel's Frame Buffer device implementation mapped kernel memory to user space via the mmap syscall. A local user able to access a frame buffer device file could possibly use this flaw to escalate their privileges on the system.