{"id":"CVE-2026-99115","aliases":[],"title":"ksmbd: fill in FileSysIdentifier in FS_POSIX_INFORMATION","titleSource":"Linux","descriptionSource":"Linux","products":[{"vendor":"Linux","name":"Linux","platforms":[],"versions":[{"version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","status":"affected","lessThan":"beba2ef6f66a71f20531ac70a1acb0b221e362e9","versionType":"git"},{"version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","status":"affected","lessThan":"ab057f271ef60ff8163818badc3de75c480eca07","versionType":"git"},{"version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","status":"affected","lessThan":"db2267b27c054a6c2151ff7fbb67927e784f31d6","versionType":"git"}],"defaultStatus":"unaffected","source":"Linux","url":"https://www.cve.org/CVERecord?id=CVE-2026-99115"},{"vendor":"Linux","name":"Linux","platforms":[],"versions":[{"version":"5.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.15","versionType":"semver"},{"version":"6.18.59","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.13","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"defaultStatus":"affected","source":"Linux","url":"https://www.cve.org/CVERecord?id=CVE-2026-99115"}],"remediation":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fill in FileSysIdentifier in FS_POSIX_INFORMATION\n\nsmb2_get_info_filesystem() reports 56 bytes for FS_POSIX_INFORMATION,\nthat is the whole of FILE_SYSTEM_POSIX_INFO, but never assigns\nFileSysIdentifier.  Those eight bytes go to the client as they are found\nin the response buffer.\n\nThe buffer is zeroed on allocation, so a standalone request leaks\nnothing.  A compound request can leak: the offset of the next response\nis advanced by the length pinned for the previous one, so a reply that\nwas written into the buffer and then dropped in favour of the short\nerror response of smb2_set_err_rsp() stays there, and the next reply is\nlaid over it with only the header cleared.\n\nReport the file system id statfs() returned, which is what the field is\nfor.  FileSysIdentifier is __le64 and f_fsid is a pair of ints, so\nassemble the value first, val[0] as the low half, and convert it on the\nway out.","severity":"unknown","score":null,"published":"2026-10-28T10:34:32.347Z","modified":"2026-10-28T10:34:32.347Z","withdrawn":false,"knownExploited":false,"affected":[],"references":["https://git.kernel.org/stable/c/beba2ef6f66a71f20531ac70a1acb0b221e362e9","https://git.kernel.org/stable/c/ab057f271ef60ff8163818badc3de75c480eca07","https://git.kernel.org/stable/c/db2267b27c054a6c2151ff7fbb67927e784f31d6"],"sources":[{"name":"CVE","id":"CVE-2026-99115","modified":"2026-10-28T10:34:32.347Z","url":"https://www.cve.org/CVERecord?id=CVE-2026-99115"}],"assessments":[],"sourceAffected":[],"kev":{"status":"not-listed","checkedAt":"2026-10-28T20:55:31.375Z"},"coverage":[{"source":"NVD","status":"not-checked"},{"source":"GHSA","status":"not-checked"},{"source":"EUVD","status":"not-checked"},{"source":"EPSS","status":"not-checked"}],"evidence":[]}