smb: client: reject userspace cifs.idmap descriptions
In the Linux kernel, the following vulnerability has been resolved: smb: client: reject userspace cifs.idmap descriptions cifs.idmap key descriptions carry authority-bearing fields (owner and group SIDs and uid/gid values in "os:"/"gs:"/"oi:"/"gi:" form) that the cifs.idmap upcall helper treats as kernel-originating inputs. Unlike its sibling cifs.spnego, the cifs.idmap key type has no vet_description hook, so userspace can create keys of this type through request_key(2)/add_key(2) and supply those fields without CIFS origin. A request_key(2) call with a non-NULL callout then drives a root usermodehelper upcall (/sbin/request-key -> cifs.idmap) that consumes the unvetted description in root context. Only accept cifs.idmap descriptions while CIFS is using its private root_cred to request the key. id_to_sid()/sid_to_id() already run under override_creds(root_cred), so the kernel-originated path is unaffected. This mirrors commit 3da1fdf4efbc ("smb: client: reject userspace cifs.spnego descriptions"), which applied the same restriction to cifs.spnego.
CVE-2026-97564
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-2026-97564
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": "4d79dba0e00749fa40de8ef13a9b85ce57a1603b",
"lessThan": "f29c1ec0e7d8c887a91df3f93bb4617c0ac95c6a",
"versionType": "git"
},
{
"status": "affected",
"version": "4d79dba0e00749fa40de8ef13a9b85ce57a1603b",
"lessThan": "17c93bcd17755523c21abb22cbf2a41a6eb0caaf",
"versionType": "git"
},
{
"status": "affected",
"version": "4d79dba0e00749fa40de8ef13a9b85ce57a1603b",
"lessThan": "e5964064e3fbe6325893408faff08ca33de0e2c3",
"versionType": "git"
},
{
"status": "affected",
"version": "4d79dba0e00749fa40de8ef13a9b85ce57a1603b",
"lessThan": "96751028c0d4dec785709ea3eb0ab38a4f2ded96",
"versionType": "git"
},
{
"status": "affected",
"version": "4d79dba0e00749fa40de8ef13a9b85ce57a1603b",
"lessThan": "1d3b24b16a0b013792e8f1e3ed060f0b46f537d1",
"versionType": "git"
},
{
"status": "affected",
"version": "4d79dba0e00749fa40de8ef13a9b85ce57a1603b",
"lessThan": "d9d7eeb0cea5b55b82888f443622fd8d4ee064f3",
"versionType": "git"
}
],
"programFiles": [
"fs/smb/client/cifsacl.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "3.0"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "3.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.1.189",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.158",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.111",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.53",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.7",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"fs/smb/client/cifsacl.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-97564
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #38010 · Revision 1
- Added to Heist Feed
- Publisher date