CVE-2026-97554

Not enough EPSS history yet.

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.

• git.kernel.orghttps://git.kernel.org/stable/c/c9a8b60ce140a68d172452f418137fc7ddbae7db
• git.kernel.orghttps://git.kernel.org/stable/c/da6e25842431982d5a53cf00d925b98c690f4467

No related CVEs by CWE or product.