CVE-2024-46774 powerpc/rtas: Prevent Spectre v1 gadget construction in sys_rtas()

2024-09-1807:12:31

Linux

www.cve.org

spectre v1 gadget

powerpc/rtas

linux kernel

vulnerability

bounds checks

array_index_nospec

EPSS

Percentile

9.6%

JSON

In the Linux kernel, the following vulnerability has been resolved:

powerpc/rtas: Prevent Spectre v1 gadget construction in sys_rtas()

Smatch warns:

arch/powerpc/kernel/rtas.c:1932 __do_sys_rtas() warn: potential
spectre issue ‘args.args’ [r] (local cap)

The ‘nargs’ and ‘nret’ locals come directly from a user-supplied
buffer and are used as indexes into a small stack-based array and as
inputs to copy_to_user() after they are subject to bounds checks.

Use array_index_nospec() after the bounds checks to clamp these values
for speculative execution.

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "arch/powerpc/kernel/rtas.c"
    ],
    "versions": [
      {
        "version": "1da177e4c3f4",
        "lessThan": "68d815648094",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "1da177e4c3f4",
        "lessThan": "0974d03eb479",
        "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/powerpc/kernel/rtas.c"
    ],
    "versions": [
      {
        "version": "6.10.10",
        "lessThanOrEqual": "6.10.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.11",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]