{"affected":[{"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-99256.json"},"ranges":[{"events":[{"introduced":"b29d4986d0da1a27cd35917cdb433672f5c95d7f"},{"fixed":"0c7a8cad7c96012a9157a189649e569d0390f384"},{"fixed":"f5db935d257023c3ef410bd39163b949b0e5a55d"},{"fixed":"6290507ecc0dd6dd40759729cbbbd49b1d2a63c4"},{"fixed":"8433fd005c25fd127021f67c9144a879fb585572"},{"fixed":"2f2cfa16dd0f4179bb988139dd37d00a42324f6c"},{"fixed":"73df2ff409f3db95029982fe3656329568e3715d"},{"fixed":"104f09e02038b0fc6bbb718b3976af029e15c1d0"},{"fixed":"bc9781c0247de107876f32929f1637db93a42b34"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","type":"GIT"}]},{"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-99256.json"},"package":{"ecosystem":"Linux","name":"Kernel"},"ranges":[{"events":[{"introduced":"4.12.0"},{"fixed":"5.10.273"}],"type":"ECOSYSTEM"},{"events":[{"introduced":"5.11.0"},{"fixed":"5.15.224"}],"type":"ECOSYSTEM"},{"events":[{"introduced":"5.16.0"},{"fixed":"6.1.191"}],"type":"ECOSYSTEM"},{"events":[{"introduced":"6.2.0"},{"fixed":"6.6.161"}],"type":"ECOSYSTEM"},{"events":[{"introduced":"6.7.0"},{"fixed":"6.12.115"}],"type":"ECOSYSTEM"},{"events":[{"introduced":"6.13.0"},{"fixed":"6.18.59"}],"type":"ECOSYSTEM"},{"events":[{"introduced":"6.19.0"},{"fixed":"7.2.13"}],"type":"ECOSYSTEM"}]}],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/99xxx/CVE-2026-99256.json"},"details":"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.","id":"CVE-2026-99256","modified":"2026-11-05T03:31:30.252826523Z","published":"2026-11-03T11:25:14.077Z","references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/0c7a8cad7c96012a9157a189649e569d0390f384"},{"type":"WEB","url":"https://git.kernel.org/stable/c/104f09e02038b0fc6bbb718b3976af029e15c1d0"},{"type":"WEB","url":"https://git.kernel.org/stable/c/2f2cfa16dd0f4179bb988139dd37d00a42324f6c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6290507ecc0dd6dd40759729cbbbd49b1d2a63c4"},{"type":"WEB","url":"https://git.kernel.org/stable/c/73df2ff409f3db95029982fe3656329568e3715d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/8433fd005c25fd127021f67c9144a879fb585572"},{"type":"WEB","url":"https://git.kernel.org/stable/c/bc9781c0247de107876f32929f1637db93a42b34"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f5db935d257023c3ef410bd39163b949b0e5a55d"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/99xxx/CVE-2026-99256.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-99256"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"schema_version":"1.9.2","summary":"dm cache: fix issue with background work locking"}