FKIE_CVE-2026-68147

Vulnerability from fkie_nvd - Published: 2026-08-10 13:20 - Updated: 2026-08-19 17:20
Severity
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: fscrypt: Avoid dynamic allocation in fscrypt_get_devices() When a blk_crypto_key starts being used or is evicted, fs/crypto/ calls fscrypt_get_devices() to get the filesystem's list of block devices, then iterates over them and calls blk_crypto_config_supported(), blk_crypto_start_using_key(), or blk_crypto_evict_key() on each one. Currently, the block device pointers are placed in a dynamically allocated array. This dynamic allocation is problematic because: - It can fail, especially at the fscrypt_destroy_inline_crypt_key() call site when it's invoked for inode eviction under direct reclaim. - fscrypt_destroy_inline_crypt_key() doesn't handle the failure. It just zeroizes and frees the blk_crypto_key without calling blk_crypto_evict_key(). That causes a use-after-free. For now, let's fix this in the straightforward and easily-backportable way by switching to an on-stack array. Currently the fscrypt multi-device functionality is used only by f2fs, which has a hardcoded limit of 8 block devices. An on-stack array works fine for that. (Of course, this solution won't scale up to large number of block devices. For that we'd need a different solution, like moving the block device iteration into the filesystem. Or in the case of btrfs, which will only support blk-crypto-fallback, we should make it just call blk-crypto-fallback directly, so the block devices won't be needed.)
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/4462ac3d90e897dda52ce4b6af2d526ddae835a8
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/6fe4e4b8259e1330945b5f3c9476e08473b8e0e8
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/81ea8e8221853950c47dac7164f27c63a96f8f86
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/97a688563be71ec6fefc071aff69a66c69dbe244
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/bab016bb80d74a9d1f7d4121a7fc1cb529b470e0
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/bc2d630296e0e049210ec05ff08459a6893ae749
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/crypto/inline_crypt.c",
            "fs/f2fs/super.c",
            "include/linux/fscrypt.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "bab016bb80d74a9d1f7d4121a7fc1cb529b470e0",
              "status": "affected",
              "version": "22e9947a4b2ba255888541bd0111cf00b9b16586",
              "versionType": "git"
            },
            {
              "lessThan": "4462ac3d90e897dda52ce4b6af2d526ddae835a8",
              "status": "affected",
              "version": "22e9947a4b2ba255888541bd0111cf00b9b16586",
              "versionType": "git"
            },
            {
              "lessThan": "97a688563be71ec6fefc071aff69a66c69dbe244",
              "status": "affected",
              "version": "22e9947a4b2ba255888541bd0111cf00b9b16586",
              "versionType": "git"
            },
            {
              "lessThan": "81ea8e8221853950c47dac7164f27c63a96f8f86",
              "status": "affected",
              "version": "22e9947a4b2ba255888541bd0111cf00b9b16586",
              "versionType": "git"
            },
            {
              "lessThan": "bc2d630296e0e049210ec05ff08459a6893ae749",
              "status": "affected",
              "version": "22e9947a4b2ba255888541bd0111cf00b9b16586",
              "versionType": "git"
            },
            {
              "lessThan": "6fe4e4b8259e1330945b5f3c9476e08473b8e0e8",
              "status": "affected",
              "version": "22e9947a4b2ba255888541bd0111cf00b9b16586",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/crypto/inline_crypt.c",
            "fs/f2fs/super.c",
            "include/linux/fscrypt.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.1"
            },
            {
              "lessThan": "6.1",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.183",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.148",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.101",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.42",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.6",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfscrypt: Avoid dynamic allocation in fscrypt_get_devices()\n\nWhen a blk_crypto_key starts being used or is evicted, fs/crypto/ calls\nfscrypt_get_devices() to get the filesystem\u0027s list of block devices,\nthen iterates over them and calls blk_crypto_config_supported(),\nblk_crypto_start_using_key(), or blk_crypto_evict_key() on each one.\n\nCurrently, the block device pointers are placed in a dynamically\nallocated array.  This dynamic allocation is problematic because:\n\n- It can fail, especially at the fscrypt_destroy_inline_crypt_key() call\n  site when it\u0027s invoked for inode eviction under direct reclaim.\n\n- fscrypt_destroy_inline_crypt_key() doesn\u0027t handle the failure.  It\n  just zeroizes and frees the blk_crypto_key without calling\n  blk_crypto_evict_key().  That causes a use-after-free.\n\nFor now, let\u0027s fix this in the straightforward and easily-backportable\nway by switching to an on-stack array.  Currently the fscrypt\nmulti-device functionality is used only by f2fs, which has a hardcoded\nlimit of 8 block devices.  An on-stack array works fine for that.\n\n(Of course, this solution won\u0027t scale up to large number of block\ndevices.  For that we\u0027d need a different solution, like moving the block\ndevice iteration into the filesystem.  Or in the case of btrfs, which\nwill only support blk-crypto-fallback, we should make it just call\nblk-crypto-fallback directly, so the block devices won\u0027t be needed.)"
    }
  ],
  "id": "CVE-2026-68147",
  "lastModified": "2026-08-19T17:20:31.923",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-08-10T13:20:00.597",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/4462ac3d90e897dda52ce4b6af2d526ddae835a8"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/6fe4e4b8259e1330945b5f3c9476e08473b8e0e8"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/81ea8e8221853950c47dac7164f27c63a96f8f86"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/97a688563be71ec6fefc071aff69a66c69dbe244"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/bab016bb80d74a9d1f7d4121a7fc1cb529b470e0"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/bc2d630296e0e049210ec05ff08459a6893ae749"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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