CVE-2024-38570

En el kernel de Linux, se resolvió la siguiente vulnerabilidad: gfs2: soluciona el posible use-after-free de glock al desmontar Cuando se libera un espacio de bloqueo de DLM y todavía hay bloqueos en ese espacio de bloqueo, DLM desbloqueará esos bloqueos automáticamente. El commit fb6791d100d1b comenzó a explotar este comportamiento para acelerar el desmontaje del sistema de archivos: gfs2 simplemente liberaría las glocks que no quería desbloquear y luego liberaría el espacio de bloqueo. Esto no tuvo en cuenta las devoluciones de llamada de bast para notificaciones de contención de bloqueo asincrónicas, que permanecen activas hasta que se desbloquea un bloqueo o se libera su espacio de bloqueo. Para evitar que esas devoluciones de llamada accedan a objetos desasignados, coloque las glocks que no deben desbloquearse en la lista sd_dead_glocks, libere el espacio de bloqueo y solo entonces libere esas glocks. Como medida adicional, ignore las devoluciones de llamada inesperadas de ast y bast si la glock receptora está muerta.

In the Linux kernel, the following vulnerability has been resolved: gfs2: Fix potential glock use-after-free on unmount When a DLM lockspace is released and there ares still locks in that lockspace, DLM will unlock those locks automatically. Commit fb6791d100d1b started exploiting this behavior to speed up filesystem unmount: gfs2 would simply free glocks it didn't want to unlock and then release the lockspace. This didn't take the bast callbacks for asynchronous lock contention notifications into account, which remain active until until a lock is unlocked or its lockspace is released. To prevent those callbacks from accessing deallocated objects, put the glocks that should not be unlocked on the sd_dead_glocks list, release the lockspace, and only then free those glocks. As an additional measure, ignore unexpected ast and bast callbacks if the receiving glock is dead.

Benedict Schlüter, Supraja Sridhara, Andrin Bertschi, and Shweta Shinde discovered that an untrusted hypervisor could inject malicious #VC interrupts and compromise the security guarantees of AMD SEV-SNP. This flaw is known as WeSee. A local attacker in control of the hypervisor could use this to expose sensitive information or possibly execute arbitrary code in the trusted execution environment. Several security issues were discovered in the Linux kernel. An attacker could possibly use these to compromise the system.