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
References
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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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
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- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
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- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
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