CVE-2015-8839

Múltiples condiciones de carrera en la implementación del sistema de archivos ext4 en el kernel de Linux en versiones anteriores a 4.5 permite a usuarios locales provocar una denegación de servicio (corrupción de disco) escribiendo a una página que está asociada con un archivo de usuario diferente después del manejo de hole punching desincronizado y de fallo de página.

A flaw was found in the Linux kernel when attempting to "punch a hole" in files existing on an ext4 filesystem. When punching holes into a file races with the page fault of the same area, it is possible that freed blocks remain referenced from page cache pages mapped to process' address space.

Justin Yackoski discovered that the Atheros L2 Ethernet Driver in the Linux kernel incorrectly enables scatter/gather I/O. A remote attacker could use this to obtain potentially sensitive information from kernel memory. Jann Horn discovered that eCryptfs improperly attempted to use the mmap() handler of a lower filesystem that did not implement one, causing a recursive page fault to occur. A local unprivileged attacker could use to cause a denial of service (system crash) or possibly execute arbitrary code with administrative privileges. Various other issues were also addressed.