CVE-2018-1120

Se ha encontrado un error que afecta al kernel de Linux en versiones anteriores a la 4.17. Al realizar un mmap() sobre un archivo copiado con FUSE en la memoria de un proceso que contiene argumentos de línea de comandos (o cadenas de entorno), un atacante puede hacer que las utilidades de psutils o procps (como ps o w) o cualquier otro programa que realiza una llamada read() a los archivos /proc//cmdline (o /proc//environ) se bloqueen indefinidamente (denegación de servicio) o durante un tiempo determinado (como primitiva de sincronización para otros ataques).

By mmap()ing a FUSE-backed file onto a process's memory containing command line arguments (or environment strings), an attacker can cause utilities from psutils or procps (such as ps, w) or any other program which makes a read() call to the /proc/<pid>/cmdline (or /proc/<pid>/environ) files to block indefinitely (denial of service) or for some controlled time (as a synchronization primitive for other attacks).

It was discovered that, when attempting to handle an out-of-memory situation, a null pointer dereference could be triggered in the Linux kernel in some circumstances. A local attacker could use this to cause a denial of service. Wen Xu discovered that the XFS filesystem implementation in the Linux kernel did not properly validate meta-data information. 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.