{"id":"CVE-2026-46107","revision":"80729d48de5f4e8181c4a92a63d25909","records":[{"revision":"80729d48de5f4e8181c4a92a63d25909","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-46107","aliases":[],"title":"dm-thin: fix metadata refcount underflow","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ndm-thin: fix metadata refcount underflow\n\nThere's a bug in dm-thin in the function rebalance_children. If the\ninternal btree node has one entry, the code tries to copy all btree\nentries from the node's child to the node itself and then decrement the\nchild's reference count.\n\nIf the child node is shared (it has reference count > 1), we won't free\nit, so there would be two pointers to each of the grandchildren nodes.\nBut the reference counts of the grandchildren is not increased, thus the\nreference count doesn't match the number of pointers that point to the\ngrandchildren. This results in \"device mapper: space map common: unable\nto decrement block\" errors.\n\nFix this bug by incrementing reference counts on the grandchildren if the\nbtree node is shared.","state":0,"publishedAt":"2026-05-28T09:35:13.051+00:00","modifiedAt":"2026-10-19T19:26:43.751+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/persistent-data/dm-btree-remove.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"3241b1d3e0aaafbfcd320f4d71ade629728cc4f4\",\n                            \"lessThan\": \"b719d12cb94df345e9ad2715fd0abe9afcaeb111\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"3241b1d3e0aaafbfcd320f4d71ade629728cc4f4\",\n                            \"lessThan\": \"f49b41c9eb7c6ff00df27cd49cea210abbadd8ad\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"3241b1d3e0aaafbfcd320f4d71ade629728cc4f4\",\n                            \"lessThan\": \"f06f6aededd792a754cd677c02b3d3016d868c2c\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"3241b1d3e0aaafbfcd320f4d71ade629728cc4f4\",\n                            \"lessThan\": \"12161e03d33afce781f68fa11cc6060538862fad\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"3241b1d3e0aaafbfcd320f4d71ade629728cc4f4\",\n                            \"lessThan\": \"323d252a4a378834e4fe68298ca61cfc5dd3a460\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"3241b1d3e0aaafbfcd320f4d71ade629728cc4f4\",\n                            \"lessThan\": \"85311a585a26640760cd0f3349ab9f2905691044\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"3241b1d3e0aaafbfcd320f4d71ade629728cc4f4\",\n                            \"lessThan\": \"5ec0debbcfd43596e32c1239e993de06a704e04c\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"3241b1d3e0aaafbfcd320f4d71ade629728cc4f4\",\n                            \"lessThan\": \"09a65adc7d8bbfce06392cb6d375468e2728ead5\",\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/persistent-data/dm-btree-remove.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"3.2\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"3.2\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.10.259\",\n                            \"lessThanOrEqual\": \"5.10.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.209\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.175\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.140\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.88\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.30\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.0.7\",\n                            \"lessThanOrEqual\": \"7.0.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.1\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/b719d12cb94df345e9ad2715fd0abe9afcaeb111","https://git.kernel.org/stable/c/f49b41c9eb7c6ff00df27cd49cea210abbadd8ad","https://git.kernel.org/stable/c/f06f6aededd792a754cd677c02b3d3016d868c2c","https://git.kernel.org/stable/c/12161e03d33afce781f68fa11cc6060538862fad","https://git.kernel.org/stable/c/323d252a4a378834e4fe68298ca61cfc5dd3a460","https://git.kernel.org/stable/c/85311a585a26640760cd0f3349ab9f2905691044","https://git.kernel.org/stable/c/5ec0debbcfd43596e32c1239e993de06a704e04c","https://git.kernel.org/stable/c/09a65adc7d8bbfce06392cb6d375468e2728ead5"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-46107","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-46107","identifiers":["CVE-2026-46107"]},"retained":false,"historicalAffected":[]}],"coverage":[]}