CVE-2020-25578

In FreeBSD 12.2-STABLE before r368969, 11.4-STABLE before r369047, 12.2-RELEASE before p3, 12.1-RELEASE before p13 and 11.4-RELEASE before p7 several file systems were not properly initializing the d_off field of the dirent structures returned by VOP_READDIR. In particular, tmpfs(5), smbfs(5), autofs(5) and mqueuefs(5) were failing to do so. As a result, eight uninitialized kernel stack bytes may be leaked to userspace by these file systems.

In FreeBSD 12.2-STABLE before r368969, 11.4-STABLE before r369047, 12.2-RELEASE before p3, 12.1-RELEASE before p13 and 11.4-RELEASE before p7 several file systems were not properly initializing the d_off field of the dirent structures returned by VOP_READDIR. In particular, tmpfs(5), smbfs(5), autofs(5) and mqueuefs(5) were failing to do so. As a result, eight uninitialized kernel stack bytes may be leaked to userspace by these file systems.

En FreeBSD versiones 12.2-STABLE anteriores a r368969, 11.4-STABLE anteriores a r369047, 12.2-RELEASE anteriores a p3, 12.1-RELEASE anteriores a p13 y 11.4-RELEASE anteriores a p7, varios sistemas de archivos no estaban inicializando apropiadamente el campo d_off de las estructuras dirent devueltas por VOP_READDIR. En particular, tmpfs(5), smbfs(5), autofs(5) y mqueuefs(5) no lo hicieron. Como resultado, estos sistemas de archivos pueden filtrar ocho bytes de la pila del kernel no inicializados al espacio de usuario.