CVE-2024-35987

En el kernel de Linux, se resolvió la siguiente vulnerabilidad: riscv: se corrigió la carga de kernels NOMMU de 64 bits después del inicio de la confirmación de RAM. 3335068f8721 ("riscv: use páginas PUD/P4D/PGD para el mapeo lineal") se agregó lógica para permitir el uso RAM debajo de la dirección de carga del kernel. Sin embargo, esto no funciona para NOMMU, donde PAGE_OFFSET está fijado a la dirección de carga del kernel. Dado que ese rango de memoria corresponde a los PFN por debajo de ARCH_PFN_OFFSET, la inicialización de mm se ejecuta desde el principio de mem_map y corrompe la memoria del kernel adyacente. Solucione este problema restaurando el comportamiento anterior de los núcleos NOMMU.

In the Linux kernel, the following vulnerability has been resolved: riscv: Fix loading 64-bit NOMMU kernels past the start of RAM commit 3335068f8721 ("riscv: Use PUD/P4D/PGD pages for the linear mapping") added logic to allow using RAM below the kernel load address. However, this does not work for NOMMU, where PAGE_OFFSET is fixed to the kernel load address. Since that range of memory corresponds to PFNs below ARCH_PFN_OFFSET, mm initialization runs off the beginning of mem_map and corrupts adjacent kernel memory. Fix this by restoring the previous behavior for NOMMU kernels.

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.