{"api_version":"1","generated_at":"2026-10-02T23:13:46+00:00","cve":"CVE-2026-98079","urls":{"html":"https://cve.report/CVE-2026-98079","api":"https://cve.report/api/cve/CVE-2026-98079.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-98079","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-98079"},"summary":{"title":"btrfs: zstd: fix lost wakeup when waiting for a workspace","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: zstd: fix lost wakeup when waiting for a workspace\n\nA writer can sleep forever in zstd_get_workspace() even though a workspace\nis free.  When zstd_alloc_workspace() fails, the task is queued on\nzwsm->wait and schedules unconditionally, never re-testing the pool.\nzstd_put_workspace() publishes the workspace and then calls cond_wake_up(),\nwhich only wakes when a sleeper is already visible, so a workspace returned\nbetween the failed allocation and prepare_to_wait() wakes nobody.  The\nwindow is wide: zstd_alloc_workspace() goes through kvmalloc() and may\nenter reclaim.\n\nOnly a max level workspace triggers the wakeup and one is deliberately kept\nallocated as the fallback every waiter waits for, so once its wakeup is\nlost the writer stays in TASK_UNINTERRUPTIBLE until some other task happens\nto return one.  Re-check the pool after prepare_to_wait() has published the\nwaiter, and use the workspace if one turned up.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-25 11:17:37","updated_at":"2026-09-30 14:10:59"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/0de9f31d447ae71ab08c7850a321682f8d2907c3","name":"https://git.kernel.org/stable/c/0de9f31d447ae71ab08c7850a321682f8d2907c3","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/2acb9f3d1cc8f65dc81ed55e238cbf8e5b60bff7","name":"https://git.kernel.org/stable/c/2acb9f3d1cc8f65dc81ed55e238cbf8e5b60bff7","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/d8f57049521948df5f50797141472fbbed3b0723","name":"https://git.kernel.org/stable/c/d8f57049521948df5f50797141472fbbed3b0723","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-98079","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98079","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 3f93aef535c8ea03e40cd8acf0753b3e6ed33e96 d8f57049521948df5f50797141472fbbed3b0723 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 3f93aef535c8ea03e40cd8acf0753b3e6ed33e96 0de9f31d447ae71ab08c7850a321682f8d2907c3 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 3f93aef535c8ea03e40cd8acf0753b3e6ed33e96 2acb9f3d1cc8f65dc81ed55e238cbf8e5b60bff7 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5.1","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.1 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.53 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.7 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3-rc2 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"98079","cve":"CVE-2026-98079","epss":"0.001980000","percentile":"0.085850000","score_date":"2026-09-27","updated_at":"2026-09-28 00:02:24"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["fs/btrfs/zstd.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"d8f57049521948df5f50797141472fbbed3b0723","status":"affected","version":"3f93aef535c8ea03e40cd8acf0753b3e6ed33e96","versionType":"git"},{"lessThan":"0de9f31d447ae71ab08c7850a321682f8d2907c3","status":"affected","version":"3f93aef535c8ea03e40cd8acf0753b3e6ed33e96","versionType":"git"},{"lessThan":"2acb9f3d1cc8f65dc81ed55e238cbf8e5b60bff7","status":"affected","version":"3f93aef535c8ea03e40cd8acf0753b3e6ed33e96","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["fs/btrfs/zstd.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"5.1"},{"lessThan":"5.1","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.53","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.7","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3-rc2","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.53","versionStartIncluding":"5.1","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.7","versionStartIncluding":"5.1","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc2","versionStartIncluding":"5.1","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: zstd: fix lost wakeup when waiting for a workspace\n\nA writer can sleep forever in zstd_get_workspace() even though a workspace\nis free.  When zstd_alloc_workspace() fails, the task is queued on\nzwsm->wait and schedules unconditionally, never re-testing the pool.\nzstd_put_workspace() publishes the workspace and then calls cond_wake_up(),\nwhich only wakes when a sleeper is already visible, so a workspace returned\nbetween the failed allocation and prepare_to_wait() wakes nobody.  The\nwindow is wide: zstd_alloc_workspace() goes through kvmalloc() and may\nenter reclaim.\n\nOnly a max level workspace triggers the wakeup and one is deliberately kept\nallocated as the fallback every waiter waits for, so once its wakeup is\nlost the writer stays in TASK_UNINTERRUPTIBLE until some other task happens\nto return one.  Re-check the pool after prepare_to_wait() has published the\nwaiter, and use the workspace if one turned up."}],"providerMetadata":{"dateUpdated":"2026-09-25T10:24:16.892Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/d8f57049521948df5f50797141472fbbed3b0723"},{"url":"https://git.kernel.org/stable/c/0de9f31d447ae71ab08c7850a321682f8d2907c3"},{"url":"https://git.kernel.org/stable/c/2acb9f3d1cc8f65dc81ed55e238cbf8e5b60bff7"}],"title":"btrfs: zstd: fix lost wakeup when waiting for a workspace","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-98079","datePublished":"2026-09-25T10:24:16.892Z","dateReserved":"2026-09-25T10:19:56.074Z","dateUpdated":"2026-09-25T10:24:16.892Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-25 11:17:37","lastModifiedDate":"2026-09-30 14:10:59","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"98079","Ordinal":"1","Title":"btrfs: zstd: fix lost wakeup when waiting for a workspace","CVE":"CVE-2026-98079","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"98079","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: zstd: fix lost wakeup when waiting for a workspace\n\nA writer can sleep forever in zstd_get_workspace() even though a workspace\nis free.  When zstd_alloc_workspace() fails, the task is queued on\nzwsm->wait and schedules unconditionally, never re-testing the pool.\nzstd_put_workspace() publishes the workspace and then calls cond_wake_up(),\nwhich only wakes when a sleeper is already visible, so a workspace returned\nbetween the failed allocation and prepare_to_wait() wakes nobody.  The\nwindow is wide: zstd_alloc_workspace() goes through kvmalloc() and may\nenter reclaim.\n\nOnly a max level workspace triggers the wakeup and one is deliberately kept\nallocated as the fallback every waiter waits for, so once its wakeup is\nlost the writer stays in TASK_UNINTERRUPTIBLE until some other task happens\nto return one.  Re-check the pool after prepare_to_wait() has published the\nwaiter, and use the workspace if one turned up.","Type":"Description","Title":"btrfs: zstd: fix lost wakeup when waiting for a workspace"}]}}}