{"id":"CVE-2026-99115","state":"PUBLISHED","title":"ksmbd: fill in FileSysIdentifier in FS_POSIX_INFORMATION","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.","publishedAt":"2026-10-28T10:34:32.347Z","updatedAt":"2026-10-30T12:41:53.529Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","status":"affected","lessThan":"cb9fbcaf1f3351bea771eec557fc6c4d2f35762b","versionType":"git"},{"version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","status":"affected","lessThan":"1d644ab9eac767d52c9b8dc0eb68c0085994d9b6","versionType":"git"},{"version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","status":"affected","lessThan":"da2ec27fdd7effbe4c94ec15b6c6a281800c5123","versionType":"git"},{"version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","status":"affected","lessThan":"f5c50f69a70fe22c44a50c869c8cd65fc35a0686","versionType":"git"},{"version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","status":"affected","lessThan":"beba2ef6f66a71f20531ac70a1acb0b221e362e9","versionType":"git"},{"version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","status":"affected","lessThan":"ab057f271ef60ff8163818badc3de75c480eca07","versionType":"git"},{"version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","status":"affected","lessThan":"db2267b27c054a6c2151ff7fbb67927e784f31d6","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/server/smb2pdu.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.15","versionType":"semver"},{"version":"5.15.224","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.161","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.115","status":"unaffected","lessThanOrEqual":"6.12.*","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"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/server/smb2pdu.c"]}],"references":["https://git.kernel.org/stable/c/cb9fbcaf1f3351bea771eec557fc6c4d2f35762b","https://git.kernel.org/stable/c/1d644ab9eac767d52c9b8dc0eb68c0085994d9b6","https://git.kernel.org/stable/c/da2ec27fdd7effbe4c94ec15b6c6a281800c5123","https://git.kernel.org/stable/c/f5c50f69a70fe22c44a50c869c8cd65fc35a0686","https://git.kernel.org/stable/c/beba2ef6f66a71f20531ac70a1acb0b221e362e9","https://git.kernel.org/stable/c/ab057f271ef60ff8163818badc3de75c480eca07","https://git.kernel.org/stable/c/db2267b27c054a6c2151ff7fbb67927e784f31d6"],"weaknesses":[],"ingestedAt":"2026-10-30T13:02:04.640Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/99xxx/CVE-2026-99115.json","commit":"cb14bf1b43b0c9f05f7f40eae2246263fd430780","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-99115","state":"PUBLISHED","datePublished":"2026-10-28T10:34:32.347Z","dateUpdated":"2026-10-30T12:41:53.529Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:25:14.392Z"},"containers":{"cna":{"title":"ksmbd: fill in FileSysIdentifier in FS_POSIX_INFORMATION","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","status":"affected","lessThan":"cb9fbcaf1f3351bea771eec557fc6c4d2f35762b","versionType":"git"},{"version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","status":"affected","lessThan":"1d644ab9eac767d52c9b8dc0eb68c0085994d9b6","versionType":"git"},{"version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","status":"affected","lessThan":"da2ec27fdd7effbe4c94ec15b6c6a281800c5123","versionType":"git"},{"version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","status":"affected","lessThan":"f5c50f69a70fe22c44a50c869c8cd65fc35a0686","versionType":"git"},{"version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","status":"affected","lessThan":"beba2ef6f66a71f20531ac70a1acb0b221e362e9","versionType":"git"},{"version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","status":"affected","lessThan":"ab057f271ef60ff8163818badc3de75c480eca07","versionType":"git"},{"version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","status":"affected","lessThan":"db2267b27c054a6c2151ff7fbb67927e784f31d6","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/server/smb2pdu.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.15","versionType":"semver"},{"version":"5.15.224","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.161","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.115","status":"unaffected","lessThanOrEqual":"6.12.*","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"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/server/smb2pdu.c"]}],"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"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-30T12:41:53.529Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"5.15.224"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"6.1.191"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"6.6.161"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"6.12.115"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"6.18.59"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"7.2.13"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}