CVE-2024-36891 maple_tree: fix mas_empty_area_rev() null pointer dereference

2024-05-3015:28:57

Linux

github.com

linux kernel

cve-2024-36891

null pointer dereference

fix

maple_tree

mas_empty_area_rev

6.8 Medium

AI Score

Confidence

Low

0.0004 Low

EPSS

Percentile

5.1%

JSON

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

maple_tree: fix mas_empty_area_rev() null pointer dereference

Currently the code calls mas_start() followed by mas_data_end() if the
maple state is MA_START, but mas_start() may return with the maple state
node == NULL. This will lead to a null pointer dereference when checking
information in the NULL node, which is done in mas_data_end().

Avoid setting the offset if there is no node by waiting until after the
maple state is checked for an empty or single entry state.

A user could trigger the events to cause a kernel oops by unmapping all
vmas to produce an empty maple tree, then mapping a vma that would cause
the scenario described above.

CNA Affected

[
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "54a611b60590",
        "lessThan": "883e5d542bbd",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "54a611b60590",
        "lessThan": "6c9c7c1e63b1",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "54a611b60590",
        "lessThan": "f3956791cf52",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "54a611b60590",
        "lessThan": "955a923d2809",
        "versionType": "git"
      }
    ],
    "programFiles": [
      "lib/maple_tree.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "6.1"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "6.1",
        "versionType": "custom"
      },
      {
        "status": "unaffected",
        "version": "6.1.94",
        "versionType": "custom",
        "lessThanOrEqual": "6.1.*"
      },
      {
        "status": "unaffected",
        "version": "6.6.31",
        "versionType": "custom",
        "lessThanOrEqual": "6.6.*"
      },
      {
        "status": "unaffected",
        "version": "6.8.10",
        "versionType": "custom",
        "lessThanOrEqual": "6.8.*"
      },
      {
        "status": "unaffected",
        "version": "6.9",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "lib/maple_tree.c"
    ],
    "defaultStatus": "affected"
  }
]