CVE-2018-13093

Se ha descubierto un problema en fs/xfs/xfs_icache.c en el kernel de Linux hasta la versión 4.17.3. Existe una desreferencia de puntero NULL y pánico en lookup_slow() en un puntero NULL inode->i_ops cuando se navega por rutas en una imagen xfs corrupta. Esto ocurre a causa de la ausencia de una validación correcta de que los inodes en caché estén libres durante la asignación.

An issue was discovered in the XFS filesystem in fs/xfs/xfs_icache.c in the Linux kernel. There is a NULL pointer dereference leading to a system panic in lookup_slow() on a NULL inode->i_ops pointer when doing pathwalks on a corrupted xfs image. This occurs because of a lack of proper validation that cached inodes are free during an allocation.

It was discovered that the LIO SCSI target implementation in the Linux kernel performed insufficient identifier checking in certain XCOPY requests. An attacker with access to at least one LUN in a multiple backstore environment could use this to expose sensitive information or modify data. Wen Xu discovered that the XFS filesystem implementation in the Linux kernel did not properly track inode validations. An attacker could use this to construct a malicious XFS image that, when mounted, could cause a denial of service. Various other issues were also addressed.