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selinux: recheck intermediate backing files on mprotect()

Type: advisorySource: Official CVE List1 source record

In the Linux kernel, the following vulnerability has been resolved: selinux: recheck intermediate backing files on mprotect() mprotect() can be used to bypass the SELinux checks that mmap() performs against the intermediate layers of a stacked filesystem. mmap() checks every backing layer as the request descends through the stack. mprotect() only has the lowest backing file in vma->vm_file, so it rechecks the top-level user and the lowest mounter, but skips the mounters of every layer in between. With two nested overlayfs mounts and a policy denying mounter_t -> middle_file_t:file { execute }, a direct mmap(PROT_EXEC) is denied: avc: denied { execute } for pid=71 comm="nested_exec" path="/payload" dev="overlay" ino=9 scontext=user_u:base_r:mounter_t tcontext=user_u:object_r:middle_file_t tclass=file permissive=0 while mmap(PROT_NONE) followed by mprotect(PROT_EXEC) succeeds. Preserve each intermediate path, mounter SID and file-description SID in the backing-file security blob, copying the saved entries when another backing layer is opened. Allocate the array only for nested backing files, and release it and the path references in the backing_file_free hook. During mprotect(), recheck fd { use } and the requested inode permissions for every saved mounter, and include the intermediate layers in the execmod checks. Policy for nested stacking may then need to grant intermediate mounters what a direct mmap() already requires, and execmod on intermediate labels for binaries using

Announced Source revision 1
Original source ↗

CVE-2026-98214

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-98214

Linux

Source reference: /containers/cna/affected/0/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
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Linux

Source reference: /containers/cna/affected/1/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "bc6c380c1159de52a252ed11f19a42c47f60a735",
        "lessThan": "4d50ebe5a27724e020747ffd61a051dec67cb8ec",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "8bacd09f12c27710228562e4d13163e58c5f4a45",
        "lessThan": "89376fbfdcc1a728e1775f98752cdd90b0930a00",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "d844702198395d3f80222777030f69db6be6b709",
        "lessThan": "d127c7e1f3e1231d8ac8b2738e3f00bea12afe74",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "82544d36b1729153c8aeb179e84750f0c085d3b1",
        "lessThan": "c2bbb905af2293549651b614a52ad91e0b462b60",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "82544d36b1729153c8aeb179e84750f0c085d3b1",
        "lessThan": "78fc54b934bfb2c18aad8154c7302067146946f9",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "cd0e707a927a70cdfd8bc5a512a9719a87f5ed51",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "6.6.144",
        "lessThan": "6.6.158",
        "versionType": "semver"
      },
      {
        "status": "affected",
        "version": "6.12.95",
        "lessThan": "6.12.112",
        "versionType": "semver"
      },
      {
        "status": "affected",
        "version": "6.18.38",
        "lessThan": "6.18.54",
        "versionType": "semver"
      },
      {
        "status": "affected",
        "version": "7.0.4",
        "lessThan": "7.1",
        "versionType": "semver"
      }
    ],
    "programFiles": [
      "security/selinux/hooks.c",
      "security/selinux/include/objsec.h"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "7.1"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "7.1",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "6.6.158",
        "versionType": "semver",
        "lessThanOrEqual": "6.6.*"
      },
      {
        "status": "unaffected",
        "version": "6.12.112",
        "versionType": "semver",
        "lessThanOrEqual": "6.12.*"
      },
      {
        "status": "unaffected",
        "version": "6.18.54",
        "versionType": "semver",
        "lessThanOrEqual": "6.18.*"
      },
      {
        "status": "unaffected",
        "version": "7.2.8",
        "versionType": "semver",
        "lessThanOrEqual": "7.2.*"
      },
      {
        "status": "unaffected",
        "version": "7.3",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "security/selinux/hooks.c",
      "security/selinux/include/objsec.h"
    ],
    "defaultStatus": "affected"
  }
]
Related CVEs
CVE-2026-98214

Source reference: /cveMetadata/cveId

Publisher severity

No explicit severity was provided.

Event
#38294 · Revision 1
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