{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-98684","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-09-25T10:25:14.364Z","datePublished":"2026-10-18T15:45:52.828Z","dateUpdated":"2026-10-19T09:23:54.479Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-10-19T09:23:54.479Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: flush and commit data before querying allocated ranges\n\nThe mode 0 / FALLOC_FL_KEEP_SIZE fallocate emulation for small interior\nranges in smb3_simple_fallocate_range() issues\nFSCTL_QUERY_ALLOCATED_RANGES and zero-fills any sub-range the server\nreports as an unallocated hole, to force block allocation without\nchanging file contents.\n\nThis is unsafe against Windows servers.  Per the Win32 documentation,\nFSCTL_QUERY_ALLOCATED_RANGES only reports ranges that *may* contain\nnonzero data and is explicitly not coherent with recently written data:\n\n  \"a call to FSCTL_QUERY_ALLOCATED_RANGES [after writing to a network\n   file] would not necessarily return a correct list of allocated\n   regions.  To ensure coherency [...] flush the data to the file\"\n\nfsx (generic/363) reproduces the resulting corruption against Windows\nServer 2022: a range is written, an uncached read returns the data, yet\nthe next FSCTL_QUERY_ALLOCATED_RANGES on that range reports it as a whole\nhole, so the emulation overwrites live data with zeroes.  A network trace\nconfirmed the WRITE, the READ returning data and the query returning an\nempty range list within microseconds.  Samba does not exhibit this; its\nquery is coherent with the written data.\n\nWrite back the dirty pages, drain any outstanding I/O and issue an SMB2\nFLUSH to force the server to commit the data before querying the\nallocated ranges, so the query reflects the data actually present.\n\nWith this, generic/363 passes against both Windows Server 2022 and Samba\nover 100000 fsx operations."}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/client/smb2ops.c"],"versions":[{"version":"966a3cb7c7db786452a87afdc3b48858fc4d4d6b","lessThan":"f82242fe3109a3ef72f429540b5bdde08fbfb0e4","status":"affected","versionType":"git"},{"version":"966a3cb7c7db786452a87afdc3b48858fc4d4d6b","lessThan":"bf84e44ff0ed802778eafd7ecb623635379cb506","status":"affected","versionType":"git"},{"version":"966a3cb7c7db786452a87afdc3b48858fc4d4d6b","lessThan":"aa994489bd835547c191827acc460192e147032d","status":"affected","versionType":"git"},{"version":"c406bb9ece6ef63721daab106f132ff4b4234e81","status":"affected","versionType":"git"},{"version":"2f9f4a2d0e6fcf0673ed51195e06e47abe966900","status":"affected","versionType":"git"},{"version":"5e397c943424de94879830e72c95f2679e297a76","status":"affected","versionType":"git"},{"version":"5.10.50","lessThan":"5.11","status":"affected","versionType":"semver"},{"version":"5.12.17","lessThan":"5.13","status":"affected","versionType":"semver"},{"version":"5.13.2","lessThan":"5.14","status":"affected","versionType":"semver"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/client/smb2ops.c"],"versions":[{"version":"5.14","status":"affected"},{"version":"0","lessThan":"5.14","status":"unaffected","versionType":"semver"},{"version":"6.18.56","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.2.10","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.14","versionEndExcluding":"6.18.56"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.14","versionEndExcluding":"7.2.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.14","versionEndExcluding":"7.3"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10.50"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12.17"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13.2"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/f82242fe3109a3ef72f429540b5bdde08fbfb0e4"},{"url":"https://git.kernel.org/stable/c/bf84e44ff0ed802778eafd7ecb623635379cb506"},{"url":"https://git.kernel.org/stable/c/aa994489bd835547c191827acc460192e147032d"}],"title":"smb: client: flush and commit data before querying allocated ranges","x_generator":{"engine":"bippy-1.2.0"}}}}