{"id":"CVE-2026-99256","aliases":[],"cve":{"records":[{"id":"CVE-2026-99256","source":"Linux","state":"PUBLISHED","reasons":[],"replacements":[],"disputed":false,"unsupportedWhenAssigned":false,"reserved":"2026-09-25T10:25:14.404Z","published":"2026-11-03T11:25:14.077Z","modified":"2026-11-03T11:40:45.109Z"}],"publishers":[{"name":"Linux","role":"CNA","organizationId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","modified":"2026-11-03T11:40:45.109Z"}],"references":[{"url":"https://git.kernel.org/stable/c/0c7a8cad7c96012a9157a189649e569d0390f384","tags":[],"source":"Linux"},{"url":"https://git.kernel.org/stable/c/f5db935d257023c3ef410bd39163b949b0e5a55d","tags":[],"source":"Linux"},{"url":"https://git.kernel.org/stable/c/6290507ecc0dd6dd40759729cbbbd49b1d2a63c4","tags":[],"source":"Linux"},{"url":"https://git.kernel.org/stable/c/8433fd005c25fd127021f67c9144a879fb585572","tags":[],"source":"Linux"},{"url":"https://git.kernel.org/stable/c/2f2cfa16dd0f4179bb988139dd37d00a42324f6c","tags":[],"source":"Linux"},{"url":"https://git.kernel.org/stable/c/73df2ff409f3db95029982fe3656329568e3715d","tags":[],"source":"Linux"},{"url":"https://git.kernel.org/stable/c/104f09e02038b0fc6bbb718b3976af029e15c1d0","tags":[],"source":"Linux"},{"url":"https://git.kernel.org/stable/c/bc9781c0247de107876f32929f1637db93a42b34","tags":[],"source":"Linux"}],"weaknesses":[],"applicability":[{"source":"Linux","statements":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"5.10.273"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"5.15.224"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"6.1.191"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"6.6.161"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"6.12.115"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"6.18.59"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"7.2.13"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"7.3"}]}]}]}],"prioritization":[]},"title":"dm cache: fix issue with background work locking","titleSource":"Linux","descriptionSource":"Linux","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ndm cache: fix issue with background work locking\n\ndm cache used a rw_semaphore for background_work_lock. Write locks on\nrw_semaphores have strict owner semantics, but there was no guarantee\nthat the process that locked background_work_lock was the same process\nthat unlocked it. This can be easily seen using a kernel compiled with\nCONFIG_DEBUG_RWSEMS. Given a dm cache device <cache>, run: 'dmsetup\nsuspend <cache> && dmsetup resume <cache>'. This will trigger a kernel\nwarning:\n\nDEBUG_RWSEMS_WARN_ON((rwsem_owner(sem) != current) && !rwsem_test_oflags(sem, RWSEM_NONSPINNABLE))\n\ntriggered by cache_resume(). To fix this, switch from a rw_semaphore to\na spinlock and a wait queue. dm cache already has a wait queue and\nassociated counter, migration_wait and nr_allocated_migrations, that was\ngetting woken up when background work was getting completed, but wasn't\nactually used by anything. This is replaced by the background_work queue\nand counter.","score":null,"severity":"unknown","published":"2026-11-03T11:25:14.077Z","modified":"2026-11-03T11:40:45.109Z","withdrawn":false,"knownExploited":false,"affected":[],"products":[{"vendor":"Linux","name":"Linux","platforms":[],"versions":[{"version":"b29d4986d0da1a27cd35917cdb433672f5c95d7f","status":"affected","lessThan":"0c7a8cad7c96012a9157a189649e569d0390f384","versionType":"git"},{"version":"b29d4986d0da1a27cd35917cdb433672f5c95d7f","status":"affected","lessThan":"f5db935d257023c3ef410bd39163b949b0e5a55d","versionType":"git"},{"version":"b29d4986d0da1a27cd35917cdb433672f5c95d7f","status":"affected","lessThan":"6290507ecc0dd6dd40759729cbbbd49b1d2a63c4","versionType":"git"},{"version":"b29d4986d0da1a27cd35917cdb433672f5c95d7f","status":"affected","lessThan":"8433fd005c25fd127021f67c9144a879fb585572","versionType":"git"},{"version":"b29d4986d0da1a27cd35917cdb433672f5c95d7f","status":"affected","lessThan":"2f2cfa16dd0f4179bb988139dd37d00a42324f6c","versionType":"git"},{"version":"b29d4986d0da1a27cd35917cdb433672f5c95d7f","status":"affected","lessThan":"73df2ff409f3db95029982fe3656329568e3715d","versionType":"git"},{"version":"b29d4986d0da1a27cd35917cdb433672f5c95d7f","status":"affected","lessThan":"104f09e02038b0fc6bbb718b3976af029e15c1d0","versionType":"git"},{"version":"b29d4986d0da1a27cd35917cdb433672f5c95d7f","status":"affected","lessThan":"bc9781c0247de107876f32929f1637db93a42b34","versionType":"git"}],"defaultStatus":"unaffected","cpes":[],"source":"Linux","url":"https://www.cve.org/CVERecord?id=CVE-2026-99256"},{"vendor":"Linux","name":"Linux","platforms":[],"versions":[{"version":"4.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.12","versionType":"semver"},{"version":"5.10.273","status":"unaffected","lessThanOrEqual":"5.10.*","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"}],"defaultStatus":"affected","cpes":[],"source":"Linux","url":"https://www.cve.org/CVERecord?id=CVE-2026-99256"}],"remediation":[],"references":["https://git.kernel.org/stable/c/0c7a8cad7c96012a9157a189649e569d0390f384","https://git.kernel.org/stable/c/f5db935d257023c3ef410bd39163b949b0e5a55d","https://git.kernel.org/stable/c/6290507ecc0dd6dd40759729cbbbd49b1d2a63c4","https://git.kernel.org/stable/c/8433fd005c25fd127021f67c9144a879fb585572","https://git.kernel.org/stable/c/2f2cfa16dd0f4179bb988139dd37d00a42324f6c","https://git.kernel.org/stable/c/73df2ff409f3db95029982fe3656329568e3715d","https://git.kernel.org/stable/c/104f09e02038b0fc6bbb718b3976af029e15c1d0","https://git.kernel.org/stable/c/bc9781c0247de107876f32929f1637db93a42b34"],"sources":[{"name":"CVE","id":"CVE-2026-99256","modified":"2026-11-03T11:40:45.109Z","url":"https://www.cve.org/CVERecord?id=CVE-2026-99256"}],"assessments":[],"sourceAffected":[],"observedAt":"2026-11-03T11:45:41.590Z","kev":{"status":"not-listed","checkedAt":"2026-11-06T21:20:33.816Z"},"coverage":[{"source":"NVD","status":"no-result","checkedAt":"2026-11-03T11:40:33.445Z","attemptedAt":"2026-11-03T11:40:33.445Z"},{"source":"GHSA","status":"no-result","checkedAt":"2026-11-03T11:40:33.640Z","attemptedAt":"2026-11-03T11:40:33.640Z"},{"source":"EUVD","status":"no-result","checkedAt":"2026-11-03T11:40:33.641Z","attemptedAt":"2026-11-03T11:40:33.641Z"},{"source":"EPSS","status":"no-result","checkedAt":"2026-11-03T11:40:33.417Z","attemptedAt":"2026-11-03T11:40:33.417Z"}],"evidence":[],"aiSummary":null}