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.
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.
Metrics
Affected Vendors & Products
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Fri, 25 Sep 2026 10:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | smb: client: avoid using uninitialized SIDs in cifs_posix_to_fattr() | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Projects
Sign in to view the affected projects.
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-09-25T10:21:45.851Z
Reserved: 2026-09-24T16:01:01.154Z
Link: CVE-2026-97554
No data.
Status : Received
Published: 2026-09-25T11:17:05.860
Modified: 2026-09-25T11:17:05.860
Link: CVE-2026-97554
No data.
OpenCVE Enrichment
Updated: 2026-09-25T16:00:16Z
Weaknesses
No weakness.