CVE-2026-97554 (GCVE-0-2026-97554)
Vulnerability from cvelistv5
Published
2026-09-25 10:21
Modified
2026-10-30 12:37
Severity ?
VLAI Severity ?
EPSS score ?
Summary
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.
References
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Linux | Linux |
Version: 9934430e2178d5164eb1ac91a9b092f9e7e64745 Version: 9934430e2178d5164eb1ac91a9b092f9e7e64745 Version: 9934430e2178d5164eb1ac91a9b092f9e7e64745 Version: 9934430e2178d5164eb1ac91a9b092f9e7e64745 Version: 9934430e2178d5164eb1ac91a9b092f9e7e64745 Version: 9934430e2178d5164eb1ac91a9b092f9e7e64745 Version: dd80b98bdf0a4b3206739f3513b0518f27a7b4ef Version: d8e39c11f66125f49de55537a6efc8ecadf4a0f7 Version: 5.8.17 ≤ Version: 5.9.2 ≤ |
||
{
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{
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{
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"status": "unaffected",
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{
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"status": "unaffected",
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{
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"status": "unaffected",
"version": "7.2.7",
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}
],
"cpeApplicability": [
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],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: avoid using uninitialized SIDs in cifs_posix_to_fattr()\n\ncifs_posix_to_fattr() ignores the return value of posix_info_parse().\nWhen a malformed POSIX directory entry is encountered (e.g. invalid\nSID lengths from an untrusted server), posix_info_parse() returns -1\nwithout populating the \u0027parsed\u0027 struct. The uninitialized stack\nmemory in parsed.owner and parsed.group is then passed to\nsid_to_id(), which processes the garbage bytes and passes them to\nrequest_key() to construct a SID string, potentially leaking kernel\nstack contents to the userspace idmap daemon.\n\nFix this by checking the return value and skipping the SID-to-id\nmapping when parsing fails. The remaining fattr fields (timestamps,\nmode, etc.) are populated directly from the \u0027info\u0027 pointer so they\nare unaffected."
}
],
"providerMetadata": {
"dateUpdated": "2026-10-30T12:37:18.935Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/1915b69e36906968e2b698699d0f219875ae846e"
},
{
"url": "https://git.kernel.org/stable/c/604feb3e8141bf11f5afd48d36d401fee5af9536"
},
{
"url": "https://git.kernel.org/stable/c/33106019c3be57b5fc6411cfaad6d98214a51265"
},
{
"url": "https://git.kernel.org/stable/c/2be31f252ade791b84f7164991f14436aed1d4b9"
},
{
"url": "https://git.kernel.org/stable/c/c9a8b60ce140a68d172452f418137fc7ddbae7db"
},
{
"url": "https://git.kernel.org/stable/c/da6e25842431982d5a53cf00d925b98c690f4467"
}
],
"title": "smb: client: avoid using uninitialized SIDs in cifs_posix_to_fattr()",
"x_generator": {
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}
},
"cveMetadata": {
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"assignerShortName": "Linux",
"cveId": "CVE-2026-97554",
"datePublished": "2026-09-25T10:21:45.851Z",
"dateReserved": "2026-09-24T16:01:01.154Z",
"dateUpdated": "2026-10-30T12:37:18.935Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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