{"id":"CVE-2026-99256","revision":"8ef96c5d139245a0b5fb2b4714404fb0","records":[{"revision":"8ef96c5d139245a0b5fb2b4714404fb0","observedAt":"2026-11-03T12:57:16.958+00:00","statement":{"source":"cve-program","id":"CVE-2026-99256","aliases":[],"title":"dm cache: fix issue with background work locking","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.","state":0,"publishedAt":"2026-11-03T11:25:14.077+00:00","modifiedAt":"2026-11-03T11:40:45.109+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                        \"drivers/md/dm-cache-target.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"b29d4986d0da1a27cd35917cdb433672f5c95d7f\",\n                            \"lessThan\": \"0c7a8cad7c96012a9157a189649e569d0390f384\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"b29d4986d0da1a27cd35917cdb433672f5c95d7f\",\n                            \"lessThan\": \"f5db935d257023c3ef410bd39163b949b0e5a55d\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"b29d4986d0da1a27cd35917cdb433672f5c95d7f\",\n                            \"lessThan\": \"6290507ecc0dd6dd40759729cbbbd49b1d2a63c4\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"b29d4986d0da1a27cd35917cdb433672f5c95d7f\",\n                            \"lessThan\": \"8433fd005c25fd127021f67c9144a879fb585572\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"b29d4986d0da1a27cd35917cdb433672f5c95d7f\",\n                            \"lessThan\": \"2f2cfa16dd0f4179bb988139dd37d00a42324f6c\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"b29d4986d0da1a27cd35917cdb433672f5c95d7f\",\n                            \"lessThan\": \"73df2ff409f3db95029982fe3656329568e3715d\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"b29d4986d0da1a27cd35917cdb433672f5c95d7f\",\n                            \"lessThan\": \"104f09e02038b0fc6bbb718b3976af029e15c1d0\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"b29d4986d0da1a27cd35917cdb433672f5c95d7f\",\n                            \"lessThan\": \"bc9781c0247de107876f32929f1637db93a42b34\",\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                        \"drivers/md/dm-cache-target.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"4.12\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"4.12\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.10.273\",\n                            \"lessThanOrEqual\": \"5.10.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.224\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.191\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.161\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.115\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.59\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.13\",\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/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"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-99256","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-99256","identifiers":["CVE-2026-99256"]},"retained":false,"historicalAffected":[]}],"coverage":[]}