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FKIE_CVE-2026-74486

Vulnerability from fkie_nvd - Published: 2026-08-15 13:17 - Updated: 2026-08-23 13:16
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: binfmt_misc: use exe_file_deny_write_access() for the interpreter clone For MISC_FMT_OPEN_FILE entries load_misc_binary() clones the registered interpreter file and denies write access to the clone via plain deny_write_access(). The clone is installed as bprm->interpreter and later released by the exec machinery through exe_file_allow_write_access() which skips the i_writecount increment for files with FMODE_FSNOTIFY_HSM set. The deny and allow side can therefore come to different conclusions when pre-content watches are in play: if a pre-content watch is added to the interpreter after registration every subsequent exec through that entry takes a write denial on the clone that is never paired with a write allowance, driving the interpreter inode's i_writecount further down with each exec and leaving the interpreter unwritable even after the entry and all its users are gone. Take the write denial via exe_file_deny_write_access() so both sides of the pairing base their decision on the same file mode, and propagate failure instead of silently ignoring it: an interpreter that is concurrently open for writing now fails the exec with ETXTBSY, exactly like an interpreter freshly opened via open_exec() would.
Impacted products
Vendor Product Version

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/binfmt_misc.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "c65eb018c12179b5e2c7afe1f0956298576fecec",
              "status": "affected",
              "version": "5b432413f7bbbc8b935138490a57be05c1921684",
              "versionType": "git"
            },
            {
              "lessThan": "2bd860b7e752a51185960143cab9fec7bf32c84e",
              "status": "affected",
              "version": "bb4715098d8e340bbbdd3a874b31f89867c8067e",
              "versionType": "git"
            },
            {
              "lessThan": "eea4b7c7711b1e425272d23352af157f45f4c3e3",
              "status": "affected",
              "version": "c152be5adc0975c75cc4f50891c9072d52d60b47",
              "versionType": "git"
            },
            {
              "lessThan": "2fdf8b07bee5ef99ec77773a6be05fbb8ee5cdb9",
              "status": "affected",
              "version": "bf5ed2ef5cdb7b47ce606e3d48ea6eb803b31503",
              "versionType": "git"
            },
            {
              "lessThan": "f1e7ea3c8e070f19771cdaef55bbeda1359ad490",
              "status": "affected",
              "version": "483217fd6f7ccd98b3ed2531a54f75ed144b4499",
              "versionType": "git"
            },
            {
              "lessThan": "255a758697da87a205e072e0cfc35897b8f743b1",
              "status": "affected",
              "version": "0357ef03c94ef835bd44a0658b8edb672a9dbf51",
              "versionType": "git"
            },
            {
              "lessThan": "f0edbaf487e4653a680a7abb91c1df94cb7886aa",
              "status": "affected",
              "version": "0357ef03c94ef835bd44a0658b8edb672a9dbf51",
              "versionType": "git"
            },
            {
              "lessThan": "fa5990ca8fd917003e526036bcc50413edb9722c",
              "status": "affected",
              "version": "0357ef03c94ef835bd44a0658b8edb672a9dbf51",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/binfmt_misc.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.14"
            },
            {
              "lessThan": "6.14",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.44",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.8",
              "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\nbinfmt_misc: use exe_file_deny_write_access() for the interpreter clone\n\nFor MISC_FMT_OPEN_FILE entries load_misc_binary() clones the\nregistered interpreter file and denies write access to the clone via\nplain deny_write_access(). The clone is installed as\nbprm-\u003einterpreter and later released by the exec machinery through\nexe_file_allow_write_access() which skips the i_writecount increment\nfor files with FMODE_FSNOTIFY_HSM set.\n\nThe deny and allow side can therefore come to different conclusions\nwhen pre-content watches are in play: if a pre-content watch is added\nto the interpreter after registration every subsequent exec through\nthat entry takes a write denial on the clone that is never paired\nwith a write allowance, driving the interpreter inode\u0027s i_writecount\nfurther down with each exec and leaving the interpreter unwritable\neven after the entry and all its users are gone.\n\nTake the write denial via exe_file_deny_write_access() so both sides\nof the pairing base their decision on the same file mode, and\npropagate failure instead of silently ignoring it: an interpreter\nthat is concurrently open for writing now fails the exec with\nETXTBSY, exactly like an interpreter freshly opened via open_exec()\nwould."
    }
  ],
  "id": "CVE-2026-74486",
  "lastModified": "2026-08-23T13:16:44.640",
  "metrics": {},
  "published": "2026-08-15T13:17:53.497",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/255a758697da87a205e072e0cfc35897b8f743b1"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/2bd860b7e752a51185960143cab9fec7bf32c84e"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/2fdf8b07bee5ef99ec77773a6be05fbb8ee5cdb9"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/c65eb018c12179b5e2c7afe1f0956298576fecec"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/eea4b7c7711b1e425272d23352af157f45f4c3e3"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/f0edbaf487e4653a680a7abb91c1df94cb7886aa"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/f1e7ea3c8e070f19771cdaef55bbeda1359ad490"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/fa5990ca8fd917003e526036bcc50413edb9722c"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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