{"id":"CVE-2025-40307","revision":"e09d824e3dbc4f9a8c74c14b30bc71ae","records":[{"revision":"e09d824e3dbc4f9a8c74c14b30bc71ae","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2025-40307","aliases":[],"title":"exfat: validate cluster allocation bits of the allocation bitmap","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nexfat: validate cluster allocation bits of the allocation bitmap\n\nsyzbot created an exfat image with cluster bits not set for the allocation\nbitmap. exfat-fs reads and uses the allocation bitmap without checking\nthis. The problem is that if the start cluster of the allocation bitmap\nis 6, cluster 6 can be allocated when creating a directory with mkdir.\nexfat zeros out this cluster in exfat_mkdir, which can delete existing\nentries. This can reallocate the allocated entries. In addition,\nthe allocation bitmap is also zeroed out, so cluster 6 can be reallocated.\nThis patch adds exfat_test_bitmap_range to validate that clusters used for\nthe allocation bitmap are correctly marked as in-use.","state":0,"publishedAt":"2025-12-08T00:46:32.659+00:00","modifiedAt":"2026-10-15T22:02:43.363+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/exfat/balloc.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"1acf1a564b6034b5af1e7fb23cb98cb3bb4f6003\",\n                            \"lessThan\": \"87f827d53bd0688597bda63ae95908e2ad39bac0\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"1acf1a564b6034b5af1e7fb23cb98cb3bb4f6003\",\n                            \"lessThan\": \"67ce8034dc0278ddd88cad93d4218a945180dddd\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"1acf1a564b6034b5af1e7fb23cb98cb3bb4f6003\",\n                            \"lessThan\": \"6bc58b4c53795ab5fe00648344aa7d9d61175f90\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"1acf1a564b6034b5af1e7fb23cb98cb3bb4f6003\",\n                            \"lessThan\": \"13c1d24803d5b0446b3f6f0fdd67e07ac1fdc7bf\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"1acf1a564b6034b5af1e7fb23cb98cb3bb4f6003\",\n                            \"lessThan\": \"79c1587b6cda74deb0c86fc7ba194b92958c793c\",\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/exfat/balloc.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"5.7\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"5.7\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.183\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.148\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.58\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.17.8\",\n                            \"lessThanOrEqual\": \"6.17.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18\",\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/87f827d53bd0688597bda63ae95908e2ad39bac0","https://git.kernel.org/stable/c/67ce8034dc0278ddd88cad93d4218a945180dddd","https://git.kernel.org/stable/c/6bc58b4c53795ab5fe00648344aa7d9d61175f90","https://git.kernel.org/stable/c/13c1d24803d5b0446b3f6f0fdd67e07ac1fdc7bf","https://git.kernel.org/stable/c/79c1587b6cda74deb0c86fc7ba194b92958c793c"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2025-40307","license":"CVE Program Terms of Use","key":"cve-program:CVE-2025-40307","identifiers":["CVE-2025-40307"]},"retained":false,"historicalAffected":[]}],"coverage":[]}