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cvelistLinuxCVELIST:CVE-2021-46945
HistoryFeb 27, 2024 - 6:40 p.m.

CVE-2021-46945 ext4: always panic when errors=panic is specified

2024-02-2718:40:31
Linux
www.cve.org
12
linux kernel
ext4
vulnerability
resolved
panic
errors=panic
mount option
remount
consistent behavior

AI Score

5.8

Confidence

High

EPSS

0

Percentile

5.1%

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

ext4: always panic when errors=panic is specified

Before commit 014c9caa29d3 (“ext4: make ext4_abort() use
__ext4_error()”), the following series of commands would trigger a
panic:

  1. mount /dev/sda -o ro,errors=panic test
  2. mount /dev/sda -o remount,abort test

After commit 014c9caa29d3, remounting a file system using the test
mount option “abort” will no longer trigger a panic. This commit will
restore the behaviour immediately before commit 014c9caa29d3.
(However, note that the Linux kernel’s behavior has not been
consistent; some previous kernel versions, including 5.4 and 4.19
similarly did not panic after using the mount option “abort”.)

This also makes a change to long-standing behaviour; namely, the
following series commands will now cause a panic, when previously it
did not:

  1. mount /dev/sda -o ro,errors=panic test
  2. echo test > /sys/fs/ext4/sda/trigger_fs_error

However, this makes ext4’s behaviour much more consistent, so this is
a good thing.

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "fs/ext4/super.c"
    ],
    "versions": [
      {
        "version": "014c9caa29d3",
        "lessThan": "64e1eebe2131",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "014c9caa29d3",
        "lessThan": "1e9ea8f46370",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "014c9caa29d3",
        "lessThan": "ac2f7ca51b09",
        "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/ext4/super.c"
    ],
    "versions": [
      {
        "version": "5.11",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "5.11",
        "status": "unaffected",
        "versionType": "semver"
      },
      {
        "version": "5.11.20",
        "lessThanOrEqual": "5.11.*",
        "status": "unaffected",
        "versionType": "semver"
      },
      {
        "version": "5.12.3",
        "lessThanOrEqual": "5.12.*",
        "status": "unaffected",
        "versionType": "semver"
      },
      {
        "version": "5.13",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]

AI Score

5.8

Confidence

High

EPSS

0

Percentile

5.1%