CVE-2024-35987 riscv: Fix loading 64-bit NOMMU kernels past the start of RAM

2024-05-2009:47:53

Linux

www.cve.org

linux kernel

vulnerability

riscv

nommu

ram

6.4 Medium

AI Score

Confidence

High

0.0004 Low

EPSS

Percentile

15.6%

JSON

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.

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "arch/riscv/include/asm/page.h",
      "arch/riscv/mm/init.c"
    ],
    "versions": [
      {
        "version": "3335068f8721",
        "lessThan": "b008e327fa57",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "3335068f8721",
        "lessThan": "ea6628e4e235",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "3335068f8721",
        "lessThan": "aea702dde7e9",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "arch/riscv/include/asm/page.h",
      "arch/riscv/mm/init.c"
    ],
    "versions": [
      {
        "version": "6.4",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "6.4",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.6.30",
        "lessThanOrEqual": "6.6.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.8.9",
        "lessThanOrEqual": "6.8.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.9",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]