CVE-2024-26590 erofs: fix inconsistent per-file compression format

2024-02-2216:13:34

Linux

www.cve.org

linux kernel

vulnerability

erofs

compression algorithms

syzkaller

crafted images

microlzma

decompressor

null pointer

superblock

bitmap

5.8 Medium

AI Score

Confidence

High

0.0004 Low

EPSS

Percentile

5.1%

JSON

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

erofs: fix inconsistent per-file compression format

EROFS can select compression algorithms on a per-file basis, and each
per-file compression algorithm needs to be marked in the on-disk
superblock for initialization.

However, syzkaller can generate inconsistent crafted images that use
an unsupported algorithmtype for specific inodes, e.g. use MicroLZMA
algorithmtype even it’s not set in sbi->available_compr_algs. This
can lead to an unexpected “BUG: kernel NULL pointer dereference” if
the corresponding decompressor isn’t built-in.

Fix this by checking against sbi->available_compr_algs for each
m_algorithmformat request. Incorrect !erofs_sb_has_compr_cfgs preset
bitmap is now fixed together since it was harmless previously.

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "fs/erofs/decompressor.c",
      "fs/erofs/zmap.c"
    ],
    "versions": [
      {
        "version": "8f89926290c4",
        "lessThan": "47467e04816c",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "8f89926290c4",
        "lessThan": "823ba1d21060",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "8f89926290c4",
        "lessThan": "eed24b816e50",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "8f89926290c4",
        "lessThan": "118a8cf504d7",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "fs/erofs/decompressor.c",
      "fs/erofs/zmap.c"
    ],
    "versions": [
      {
        "version": "5.16",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "5.16",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.1.80",
        "lessThanOrEqual": "6.1.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.6.14",
        "lessThanOrEqual": "6.6.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.7.2",
        "lessThanOrEqual": "6.7.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.8",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]