{"id":"CVE-2026-98079","revision":"76ca2e071f3e4c2395ad6ff1874e23db","records":[{"revision":"76ca2e071f3e4c2395ad6ff1874e23db","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-98079","aliases":[],"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":0,"publishedAt":"2026-09-25T10:24:16.892+00:00","modifiedAt":"2026-10-21T12:54:23.769+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"fs/btrfs/zstd.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"3f93aef535c8ea03e40cd8acf0753b3e6ed33e96\",\n                            \"lessThan\": \"14d982762945d9945c60bbd48b77df194dd8e28d\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"3f93aef535c8ea03e40cd8acf0753b3e6ed33e96\",\n                            \"lessThan\": \"844603cf842ee67640d33f350e3fa60f3de7fad3\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"3f93aef535c8ea03e40cd8acf0753b3e6ed33e96\",\n                            \"lessThan\": \"d8f57049521948df5f50797141472fbbed3b0723\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"3f93aef535c8ea03e40cd8acf0753b3e6ed33e96\",\n                            \"lessThan\": \"0de9f31d447ae71ab08c7850a321682f8d2907c3\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"3f93aef535c8ea03e40cd8acf0753b3e6ed33e96\",\n                            \"lessThan\": \"2acb9f3d1cc8f65dc81ed55e238cbf8e5b60bff7\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"fs/btrfs/zstd.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"5.1\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"5.1\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.160\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.114\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.53\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.7\",\n                            \"lessThanOrEqual\": \"7.2.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.3\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[],"references":["https://git.kernel.org/stable/c/14d982762945d9945c60bbd48b77df194dd8e28d","https://git.kernel.org/stable/c/844603cf842ee67640d33f350e3fa60f3de7fad3","https://git.kernel.org/stable/c/d8f57049521948df5f50797141472fbbed3b0723","https://git.kernel.org/stable/c/0de9f31d447ae71ab08c7850a321682f8d2907c3","https://git.kernel.org/stable/c/2acb9f3d1cc8f65dc81ed55e238cbf8e5b60bff7"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98079","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-98079","identifiers":["CVE-2026-98079"]},"retained":false,"historicalAffected":[]}],"coverage":[]}