fhandle: reject detached mounts in capable_wrt_mount()
In the Linux kernel, the following vulnerability has been resolved: fhandle: reject detached mounts in capable_wrt_mount() The recent fhandle RCU fix moved the mount namespace capability check into capable_wrt_mount(), so a non-NULL mnt_namespace survives the ns_capable() dereference. The helper still assumes the later READ_ONCE(mount->mnt_ns) must be non-NULL because may_decode_fh() checked is_mounted() first. That assumption is not stable. A detached mount from open_tree(..., OPEN_TREE_CLONE) can be dissolved on fput while open_by_handle_at() is between those checks, and umount_tree() can clear mount->mnt_ns. If the helper observes NULL, it dereferences mnt_ns->user_ns and panics. Return false when the RCU read observes a detached mount. This keeps the relaxed permission path conservative: a mount no longer attached to a namespace cannot authorize open_by_handle_at() access.
CVE-2026-72034
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-2026-72034
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
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": "620c266f394932e5decc4b34683a75dfc59dc2f4",
"lessThan": "15104234c267ebe04b9f9a73e5c2179cc265ff60",
"versionType": "git"
},
{
"status": "affected",
"version": "620c266f394932e5decc4b34683a75dfc59dc2f4",
"lessThan": "6c52226072a3c61337b1eec1799bb987748884fa",
"versionType": "git"
},
{
"status": "affected",
"version": "620c266f394932e5decc4b34683a75dfc59dc2f4",
"lessThan": "6ee183d89261bf1d1cf9f06d80a40dab8f36ee55",
"versionType": "git"
},
{
"status": "affected",
"version": "620c266f394932e5decc4b34683a75dfc59dc2f4",
"lessThan": "6c732471740bc2ac9b0946134f9f551dc75f4369",
"versionType": "git"
}
],
"programFiles": [
"fs/fhandle.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.11"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.11",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.12.97",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.40",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.1.5",
"versionType": "semver",
"lessThanOrEqual": "7.1.*"
},
{
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"fs/fhandle.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-72034
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #41841 · Revision 1
- Added to Heist Feed
- Publisher date