CVE-2024-26601 ext4: regenerate buddy after block freeing failed if under fc replay

2024-02-2414:56:56

Linux

github.com

linux kernel

ext4

vulnerability mitigation

block freeing

buddy regeneration

fast commit replay

6.8 Medium

AI Score

Confidence

High

0.0004 Low

EPSS

Percentile

5.1%

JSON

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

ext4: regenerate buddy after block freeing failed if under fc replay

This mostly reverts commit 6bd97bf273bd (“ext4: remove redundant
mb_regenerate_buddy()”) and reintroduces mb_regenerate_buddy(). Based on
code in mb_free_blocks(), fast commit replay can end up marking as free
blocks that are already marked as such. This causes corruption of the
buddy bitmap so we need to regenerate it in that case.

CNA Affected

[
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "0983142c5f17",
        "lessThan": "94ebf71bddbc",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "6bd97bf273bd",
        "lessThan": "c1317822e2de",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "6bd97bf273bd",
        "lessThan": "78327acd4cdc",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "6bd97bf273bd",
        "lessThan": "ea42d6cffb0d",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "6bd97bf273bd",
        "lessThan": "6b0d48647935",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "6bd97bf273bd",
        "lessThan": "c9b528c35795",
        "versionType": "git"
      }
    ],
    "programFiles": [
      "fs/ext4/mballoc.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "5.11"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "5.11",
        "versionType": "custom"
      },
      {
        "status": "unaffected",
        "version": "5.10.211",
        "versionType": "custom",
        "lessThanOrEqual": "5.10.*"
      },
      {
        "status": "unaffected",
        "version": "5.15.150",
        "versionType": "custom",
        "lessThanOrEqual": "5.15.*"
      },
      {
        "status": "unaffected",
        "version": "6.1.78",
        "versionType": "custom",
        "lessThanOrEqual": "6.1.*"
      },
      {
        "status": "unaffected",
        "version": "6.6.17",
        "versionType": "custom",
        "lessThanOrEqual": "6.6.*"
      },
      {
        "status": "unaffected",
        "version": "6.7.5",
        "versionType": "custom",
        "lessThanOrEqual": "6.7.*"
      },
      {
        "status": "unaffected",
        "version": "6.8",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "fs/ext4/mballoc.c"
    ],
    "defaultStatus": "affected"
  }
]