{"id":"CVE-2026-99115","title":"ksmbd: fill in FileSysIdentifier in FS_POSIX_INFORMATION","summary":"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_I…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < cb9fbcaf1f3351bea771eec557fc6c4d2f35762b","Linux >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < 1d644ab9eac767d52c9b8dc0eb68c0085994d9b6","Linux >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < da2ec27fdd7effbe4c94ec15b6c6a281800c5123","Linux >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < f5c50f69a70fe22c44a50c869c8cd65fc35a0686","Linux >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < beba2ef6f66a71f20531ac70a1acb0b221e362e9","Linux >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < ab057f271ef60ff8163818badc3de75c480eca07","Linux >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < db2267b27c054a6c2151ff7fbb67927e784f31d6","Linux 5.15"],"published":"2026-10-28","updated":"2026-10-30","sourceUpdated":"2026-10-30T12:41:53.529Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-99115","references":[{"url":"https://git.kernel.org/stable/c/cb9fbcaf1f3351bea771eec557fc6c4d2f35762b"},{"url":"https://git.kernel.org/stable/c/1d644ab9eac767d52c9b8dc0eb68c0085994d9b6"},{"url":"https://git.kernel.org/stable/c/da2ec27fdd7effbe4c94ec15b6c6a281800c5123"},{"url":"https://git.kernel.org/stable/c/f5c50f69a70fe22c44a50c869c8cd65fc35a0686"},{"url":"https://git.kernel.org/stable/c/beba2ef6f66a71f20531ac70a1acb0b221e362e9"},{"url":"https://git.kernel.org/stable/c/ab057f271ef60ff8163818badc3de75c480eca07"},{"url":"https://git.kernel.org/stable/c/db2267b27c054a6c2151ff7fbb67927e784f31d6"}],"tags":["cve.org"],"epss":0.00173,"epssPercentile":0.06786,"ingestedAt":"2026-10-28T11:09:40.451Z","slug":"CVE-2026-99115","body":"## Overview\n\nIn 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.\n\n## Affected\n\n- `Linux >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < cb9fbcaf1f3351bea771eec557fc6c4d2f35762b`\n- `Linux >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < 1d644ab9eac767d52c9b8dc0eb68c0085994d9b6`\n- `Linux >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < da2ec27fdd7effbe4c94ec15b6c6a281800c5123`\n- `Linux >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < f5c50f69a70fe22c44a50c869c8cd65fc35a0686`\n- `Linux >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < beba2ef6f66a71f20531ac70a1acb0b221e362e9`\n- `Linux >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < ab057f271ef60ff8163818badc3de75c480eca07`\n- `Linux >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < db2267b27c054a6c2151ff7fbb67927e784f31d6`\n- `Linux 5.15`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}