smb: client: avoid using uninitialized SIDs in cifs_posix_to_fattr()
In the Linux kernel, the following vulnerability has been resolved: smb: client: avoid using uninitialized SIDs in cifs_posix_to_fattr() cifs_posix_to_fattr() ignores the return value of posix_info_parse(). When a malformed POSIX directory entry is encountered (e.g. invalid SID lengths from an untrusted server), posix_info_parse() returns -1 without populating the 'parsed' struct. The uninitialized stack memory in parsed.owner and parsed.group is then passed to sid_to_id(), which processes the garbage bytes and passes them to request_key() to construct a SID string, potentially leaking kernel stack contents to the userspace idmap daemon. Fix this by checking the return value and skipping the SID-to-id mapping when parsing fails. The remaining fattr fields (timestamps, mode, etc.) are populated directly from the 'info' pointer so they are unaffected.
CVE-2026-97554
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-2026-97554
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": "9934430e2178d5164eb1ac91a9b092f9e7e64745",
"lessThan": "604feb3e8141bf11f5afd48d36d401fee5af9536",
"versionType": "git"
},
{
"status": "affected",
"version": "9934430e2178d5164eb1ac91a9b092f9e7e64745",
"lessThan": "33106019c3be57b5fc6411cfaad6d98214a51265",
"versionType": "git"
},
{
"status": "affected",
"version": "9934430e2178d5164eb1ac91a9b092f9e7e64745",
"lessThan": "2be31f252ade791b84f7164991f14436aed1d4b9",
"versionType": "git"
},
{
"status": "affected",
"version": "9934430e2178d5164eb1ac91a9b092f9e7e64745",
"lessThan": "c9a8b60ce140a68d172452f418137fc7ddbae7db",
"versionType": "git"
},
{
"status": "affected",
"version": "9934430e2178d5164eb1ac91a9b092f9e7e64745",
"lessThan": "da6e25842431982d5a53cf00d925b98c690f4467",
"versionType": "git"
},
{
"status": "affected",
"version": "dd80b98bdf0a4b3206739f3513b0518f27a7b4ef",
"versionType": "git"
},
{
"status": "affected",
"version": "d8e39c11f66125f49de55537a6efc8ecadf4a0f7",
"versionType": "git"
},
{
"status": "affected",
"version": "5.8.17",
"lessThan": "5.9",
"versionType": "semver"
},
{
"status": "affected",
"version": "5.9.2",
"lessThan": "5.10",
"versionType": "semver"
}
],
"programFiles": [
"fs/smb/client/readdir.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.10"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.10",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.6.160",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.114",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.57",
"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/readdir.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-97554
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #48783 · Revision 1
- Added to Heist Feed
- Publisher date