CVE-2024-35987: 
Linux Kernel vulnerability analysis and mitigation

CVE-2024-35987 affects the Linux kernel, specifically related to RISC-V architecture. The vulnerability was discovered and disclosed on May 20, 2024. The issue involves incorrect handling of 64-bit NOMMU kernels when loading past the start of RAM, which was introduced by commit 3335068f8721 that added logic for using RAM below the kernel load address (Kernel Git).

The vulnerability stems from a logic issue where PAGE_OFFSET is fixed to the kernel load address in NOMMU configurations. When memory corresponds to PFNs below ARCH_PFN_OFFSET, the mm initialization process runs off the beginning of mem_map and corrupts adjacent kernel memory. This occurs specifically in the RISC-V architecture's memory management implementation (Kernel Git).

The vulnerability can lead to kernel memory corruption in systems using 64-bit NOMMU kernels on RISC-V architecture. This affects the memory management subsystem and could potentially compromise system stability (Ubuntu Security).

The vulnerability specifically affects RISC-V systems running 64-bit NOMMU kernels. It requires specific hardware architecture and kernel configuration to be exploitable (NVD).

The issue has been fixed in various Linux kernel versions. Ubuntu has released patches for affected versions, including linux-lowlatency 6.8.0-40.40.1 for Ubuntu 24.04 LTS. The fix involves restoring the previous behavior for NOMMU kernels by modifying the condition for setting kernel_map.va_pa_offset (Ubuntu Security).