{"api_version":"1","generated_at":"2026-08-15T16:26:45+00:00","cve":"CVE-2026-72132","urls":{"html":"https://cve.report/CVE-2026-72132","api":"https://cve.report/api/cve/CVE-2026-72132.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-72132","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-72132"},"summary":{"title":"NFS: Charge unstable writes by request size, not folio size","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nNFS: Charge unstable writes by request size, not folio size\n\nnfs_folio_mark_unstable() and nfs_folio_clear_commit() charge and\nuncharge NR_WRITEBACK/WB_WRITEBACK by folio_nr_pages(folio) once per\n*request* added to or removed from a commit list. This is correct only\nwhen a folio has a single associated request. When pg_test splits a\nfolio into N sub-folio requests (e.g. pNFS flexfiles striping with a\nstripe unit smaller than the folio size, or plain wsize-limited\nsplitting), each of the N requests independently charges the whole\nfolio's page count, inflating the accounting by a factor of N per\nfolio. With large folios and small stripe units this reaches multiple\norders of magnitude: a 2 MiB folio split into 512 4 KiB requests can\ncharge up to 512x its real size, pushing global dirty+writeback\naccounting past the system's dirty threshold and forcing every\nbuffered writer on the host into the hard-throttle path, including\nunrelated in-kernel NFS server threads sharing the box.\n\nCharge each request only for the pages it actually covers.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-08-15 06:21:30","updated_at":"2026-08-15 06:21:30"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/27934d02cbeb8a957dd11c985a579e58d30c5270","name":"https://git.kernel.org/stable/c/27934d02cbeb8a957dd11c985a579e58d30c5270","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/0ffc032294a29601b1019dba91aa1a930d90df17","name":"https://git.kernel.org/stable/c/0ffc032294a29601b1019dba91aa1a930d90df17","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/a192b6c149c6ea10cc88869accb78165eb454456","name":"https://git.kernel.org/stable/c/a192b6c149c6ea10cc88869accb78165eb454456","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/a442c258320b689f13d2205eaeeddf8b0e630288","name":"https://git.kernel.org/stable/c/a442c258320b689f13d2205eaeeddf8b0e630288","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/1f646e23372f3444dc5f0bcb5404a49d26756add","name":"https://git.kernel.org/stable/c/1f646e23372f3444dc5f0bcb5404a49d26756add","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-72132","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-72132","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 0c493b5cf16e28d761b6e77c7c32aa0e7af70813 a442c258320b689f13d2205eaeeddf8b0e630288 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 0c493b5cf16e28d761b6e77c7c32aa0e7af70813 1f646e23372f3444dc5f0bcb5404a49d26756add git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 0c493b5cf16e28d761b6e77c7c32aa0e7af70813 0ffc032294a29601b1019dba91aa1a930d90df17 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 0c493b5cf16e28d761b6e77c7c32aa0e7af70813 a192b6c149c6ea10cc88869accb78165eb454456 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 0c493b5cf16e28d761b6e77c7c32aa0e7af70813 27934d02cbeb8a957dd11c985a579e58d30c5270 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.3","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.3 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.148 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.97 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.40 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1.5 7.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2-rc3 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["fs/nfs/internal.h","fs/nfs/pnfs_nfs.c","fs/nfs/write.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"a442c258320b689f13d2205eaeeddf8b0e630288","status":"affected","version":"0c493b5cf16e28d761b6e77c7c32aa0e7af70813","versionType":"git"},{"lessThan":"1f646e23372f3444dc5f0bcb5404a49d26756add","status":"affected","version":"0c493b5cf16e28d761b6e77c7c32aa0e7af70813","versionType":"git"},{"lessThan":"0ffc032294a29601b1019dba91aa1a930d90df17","status":"affected","version":"0c493b5cf16e28d761b6e77c7c32aa0e7af70813","versionType":"git"},{"lessThan":"a192b6c149c6ea10cc88869accb78165eb454456","status":"affected","version":"0c493b5cf16e28d761b6e77c7c32aa0e7af70813","versionType":"git"},{"lessThan":"27934d02cbeb8a957dd11c985a579e58d30c5270","status":"affected","version":"0c493b5cf16e28d761b6e77c7c32aa0e7af70813","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["fs/nfs/internal.h","fs/nfs/pnfs_nfs.c","fs/nfs/write.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"6.3"},{"lessThan":"6.3","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.148","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.97","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.40","versionType":"semver"},{"lessThanOrEqual":"7.1.*","status":"unaffected","version":"7.1.5","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.2-rc3","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.148","versionStartIncluding":"6.3","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.97","versionStartIncluding":"6.3","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.40","versionStartIncluding":"6.3","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1.5","versionStartIncluding":"6.3","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2-rc3","versionStartIncluding":"6.3","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nNFS: Charge unstable writes by request size, not folio size\n\nnfs_folio_mark_unstable() and nfs_folio_clear_commit() charge and\nuncharge NR_WRITEBACK/WB_WRITEBACK by folio_nr_pages(folio) once per\n*request* added to or removed from a commit list. This is correct only\nwhen a folio has a single associated request. When pg_test splits a\nfolio into N sub-folio requests (e.g. pNFS flexfiles striping with a\nstripe unit smaller than the folio size, or plain wsize-limited\nsplitting), each of the N requests independently charges the whole\nfolio's page count, inflating the accounting by a factor of N per\nfolio. With large folios and small stripe units this reaches multiple\norders of magnitude: a 2 MiB folio split into 512 4 KiB requests can\ncharge up to 512x its real size, pushing global dirty+writeback\naccounting past the system's dirty threshold and forcing every\nbuffered writer on the host into the hard-throttle path, including\nunrelated in-kernel NFS server threads sharing the box.\n\nCharge each request only for the pages it actually covers."}],"providerMetadata":{"dateUpdated":"2026-08-15T05:53:08.096Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/a442c258320b689f13d2205eaeeddf8b0e630288"},{"url":"https://git.kernel.org/stable/c/1f646e23372f3444dc5f0bcb5404a49d26756add"},{"url":"https://git.kernel.org/stable/c/0ffc032294a29601b1019dba91aa1a930d90df17"},{"url":"https://git.kernel.org/stable/c/a192b6c149c6ea10cc88869accb78165eb454456"},{"url":"https://git.kernel.org/stable/c/27934d02cbeb8a957dd11c985a579e58d30c5270"}],"title":"NFS: Charge unstable writes by request size, not folio size","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-72132","datePublished":"2026-08-15T05:53:08.096Z","dateReserved":"2026-08-09T03:40:39.907Z","dateUpdated":"2026-08-15T05:53:08.096Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-08-15 06:21:30","lastModifiedDate":"2026-08-15 06:21:30","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"72132","Ordinal":"1","Title":"NFS: Charge unstable writes by request size, not folio size","CVE":"CVE-2026-72132","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"72132","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nNFS: Charge unstable writes by request size, not folio size\n\nnfs_folio_mark_unstable() and nfs_folio_clear_commit() charge and\nuncharge NR_WRITEBACK/WB_WRITEBACK by folio_nr_pages(folio) once per\n*request* added to or removed from a commit list. This is correct only\nwhen a folio has a single associated request. When pg_test splits a\nfolio into N sub-folio requests (e.g. pNFS flexfiles striping with a\nstripe unit smaller than the folio size, or plain wsize-limited\nsplitting), each of the N requests independently charges the whole\nfolio's page count, inflating the accounting by a factor of N per\nfolio. With large folios and small stripe units this reaches multiple\norders of magnitude: a 2 MiB folio split into 512 4 KiB requests can\ncharge up to 512x its real size, pushing global dirty+writeback\naccounting past the system's dirty threshold and forcing every\nbuffered writer on the host into the hard-throttle path, including\nunrelated in-kernel NFS server threads sharing the box.\n\nCharge each request only for the pages it actually covers.","Type":"Description","Title":"NFS: Charge unstable writes by request size, not folio size"}]}}}