smb: client: avoid using uninitialized SIDs in cifs_posix_to_fattr()
Summary
| CVE | CVE-2026-97554 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-25 11:17:05 UTC |
| Updated | 2026-10-21 13:21:13 UTC |
| Description | 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. |
Risk And Classification
EPSS: 0.001980000 probability, percentile 0.090370000 (date 2026-10-21)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected 9934430e2178d5164eb1ac91a9b092f9e7e64745 604feb3e8141bf11f5afd48d36d401fee5af9536 git | Not specified |
| CNA | Linux | Linux | affected 9934430e2178d5164eb1ac91a9b092f9e7e64745 33106019c3be57b5fc6411cfaad6d98214a51265 git | Not specified |
| CNA | Linux | Linux | affected 9934430e2178d5164eb1ac91a9b092f9e7e64745 2be31f252ade791b84f7164991f14436aed1d4b9 git | Not specified |
| CNA | Linux | Linux | affected 9934430e2178d5164eb1ac91a9b092f9e7e64745 c9a8b60ce140a68d172452f418137fc7ddbae7db git | Not specified |
| CNA | Linux | Linux | affected 9934430e2178d5164eb1ac91a9b092f9e7e64745 da6e25842431982d5a53cf00d925b98c690f4467 git | Not specified |
| CNA | Linux | Linux | affected dd80b98bdf0a4b3206739f3513b0518f27a7b4ef git | Not specified |
| CNA | Linux | Linux | affected d8e39c11f66125f49de55537a6efc8ecadf4a0f7 git | Not specified |
| CNA | Linux | Linux | affected 5.8.17 5.9 semver | Not specified |
| CNA | Linux | Linux | affected 5.9.2 5.10 semver | Not specified |
| CNA | Linux | Linux | affected 5.10 | Not specified |
| CNA | Linux | Linux | unaffected 5.10 semver | Not specified |
| CNA | Linux | Linux | unaffected 6.6.160 6.6.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.114 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.57 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.2.7 7.2.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.3 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/604feb3e8141bf11f5afd48d36d401fee5af9536 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/2be31f252ade791b84f7164991f14436aed1d4b9 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/c9a8b60ce140a68d172452f418137fc7ddbae7db | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/33106019c3be57b5fc6411cfaad6d98214a51265 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/da6e25842431982d5a53cf00d925b98c690f4467 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.