CVE-2019-19319

En el kernel de Linux anterior a la versión 5.2, una operación setxattr, posterior al montaje de una imagen ext4 especialmente diseñada, puede causar un acceso de escritura fuera de límites debido a un uso de la memoria previamente liberada de la función ext4_xattr_set_entry en el archivo fs/ext4/xattr.c cuando se usa un valor grande de old_size en una llamada memset también conocido como CID-345c0dbf3a30.

An out-of-bounds write flaw was found in the Linux kernel’s Ext4 FileSystem in the way it uses a crafted ext4 image. This flaw allows a local user with physical access to crash the system or potentially escalate their privileges on the system.

It was discovered that the ext4 file system implementation in the Linux kernel did not properly handle setxattr operations in some situations. A local attacker could use this to cause a denial of service or possibly execute arbitrary code. It was discovered that memory contents previously stored in microarchitectural special registers after RDRAND, RDSEED, and SGX EGETKEY read operations on Intel client and Xeon E3 processors may be briefly exposed to processes on the same or different processor cores. A local attacker could use this to expose sensitive information. Various other issues were also addressed.