FKIE_CVE-2026-64596

Vulnerability from fkie_nvd - Published: 2026-08-06 08:16 - Updated: 2026-08-06 08:16
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: libfs: set SB_I_NOEXEC and SB_I_NODEV by default in init_pseudo() Since commit 1e7ab6f67824 ("anon_inode: rework assertions"), path_noexec() warns when an anonymous-inode file is mmap'd from a superblock that has not set SB_I_NOEXEC. dma-buf backs its files this way and never set the flag, so mmap of any exported buffer trips the warning on a CONFIG_DEBUG_VFS=y kernel: WARNING: CPU: 11 PID: 121813 at fs/exec.c:118 path_noexec+0x47/0x50 do_mmap+0x2b5/0x680 vm_mmap_pgoff+0x129/0x210 ksys_mmap_pgoff+0x177/0x240 __x64_sys_mmap+0x33/0x70 init_pseudo() sets up internal SB_NOUSER mounts that are never path-reachable. Set both flags here so every pseudo filesystem gets them by default instead of each caller setting them. SB_I_NODEV is inert for unreachable mounts. SB_I_NOEXEC has one visible effect: an executable mapping of a pseudo-fs fd, such as a dma-buf, now fails with -EPERM, which is the invariant the assertion enforces. No in-tree caller maps these executable. Reproduce on CONFIG_DEBUG_VFS=y: make -C tools/testing/selftests/dmabuf-heaps sudo ./tools/testing/selftests/dmabuf-heaps/dmabuf-heap -t system
Impacted products
Vendor Product Version

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/libfs.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "b9d45d328fcda4f0d3d281b7d6f12d3f181d9381",
              "status": "affected",
              "version": "1e7ab6f67824343ee3e96f100f0937c393749a8a",
              "versionType": "git"
            },
            {
              "lessThan": "8e931557b317f0fb414839fa51fae1d5feb0ad97",
              "status": "affected",
              "version": "1e7ab6f67824343ee3e96f100f0937c393749a8a",
              "versionType": "git"
            },
            {
              "lessThan": "6de2aeffabaafaeda819e60ec8d04f199711e11a",
              "status": "affected",
              "version": "1e7ab6f67824343ee3e96f100f0937c393749a8a",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "9b8076a9404568d6cb6673b9a079558b15051966",
              "versionType": "git"
            },
            {
              "lessThan": "6.16",
              "status": "affected",
              "version": "6.15.6",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/libfs.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.16"
            },
            {
              "lessThan": "6.16",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.39",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2-rc1",
              "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\nlibfs: set SB_I_NOEXEC and SB_I_NODEV by default in init_pseudo()\n\nSince commit 1e7ab6f67824 (\"anon_inode: rework assertions\"),\npath_noexec() warns when an anonymous-inode file is mmap\u0027d from a\nsuperblock that has not set SB_I_NOEXEC. dma-buf backs its files this\nway and never set the flag, so mmap of any exported buffer trips the\nwarning on a CONFIG_DEBUG_VFS=y kernel:\n\n  WARNING: CPU: 11 PID: 121813 at fs/exec.c:118 path_noexec+0x47/0x50\n   do_mmap+0x2b5/0x680\n   vm_mmap_pgoff+0x129/0x210\n   ksys_mmap_pgoff+0x177/0x240\n   __x64_sys_mmap+0x33/0x70\n\ninit_pseudo() sets up internal SB_NOUSER mounts that are never\npath-reachable. Set both flags here so every pseudo filesystem gets\nthem by default instead of each caller setting them.\n\nSB_I_NODEV is inert for unreachable mounts. SB_I_NOEXEC has one\nvisible effect: an executable mapping of a pseudo-fs fd, such as a\ndma-buf, now fails with -EPERM, which is the invariant the assertion\nenforces. No in-tree caller maps these executable.\n\nReproduce on CONFIG_DEBUG_VFS=y:\n\n  make -C tools/testing/selftests/dmabuf-heaps\n  sudo ./tools/testing/selftests/dmabuf-heaps/dmabuf-heap -t system"
    }
  ],
  "id": "CVE-2026-64596",
  "lastModified": "2026-08-06T08:16:35.217",
  "metrics": {},
  "published": "2026-08-06T08:16:35.217",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/6de2aeffabaafaeda819e60ec8d04f199711e11a"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/8e931557b317f0fb414839fa51fae1d5feb0ad97"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/b9d45d328fcda4f0d3d281b7d6f12d3f181d9381"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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