{"id":"CVE-2026-45915","state":"PUBLISHED","title":"fat: avoid parent link count underflow in rmdir","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nfat: avoid parent link count underflow in rmdir\n\nCorrupted FAT images can leave a directory inode with an incorrect\ni_nlink (e.g. 2 even though subdirectories exist). rmdir then\nunconditionally calls drop_nlink(dir) and can drive i_nlink to 0,\ntriggering the WARN_ON in drop_nlink().\n\nAdd a sanity check in vfat_rmdir() and msdos_rmdir(): only drop the\nparent link count when it is at least 3, otherwise report a filesystem\nerror.","publishedAt":"2026-05-27T12:17:30.699Z","updatedAt":"2026-05-27T12:17:30.699Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"9a53c3a783c2fa9b969628e65695c11c3e51e673","status":"affected","lessThan":"7fe0de287e931e07cb96ecf1f449b2ebdb0e1115","versionType":"git"},{"version":"9a53c3a783c2fa9b969628e65695c11c3e51e673","status":"affected","lessThan":"9894c79fd9466612d0514be157b5c30cd93aa645","versionType":"git"},{"version":"9a53c3a783c2fa9b969628e65695c11c3e51e673","status":"affected","lessThan":"cd569b87378b9c33ae13c23d6bb9d205d66f7c4b","versionType":"git"},{"version":"9a53c3a783c2fa9b969628e65695c11c3e51e673","status":"affected","lessThan":"d3b7ffa90f613938128432c7b2f35b7aa4bdd86b","versionType":"git"},{"version":"9a53c3a783c2fa9b969628e65695c11c3e51e673","status":"affected","lessThan":"955c5d670b5ae07c78f4345e23a895638db96ce1","versionType":"git"},{"version":"9a53c3a783c2fa9b969628e65695c11c3e51e673","status":"affected","lessThan":"17866f8a0822d414cb02e621cf003a7d04396ef8","versionType":"git"},{"version":"9a53c3a783c2fa9b969628e65695c11c3e51e673","status":"affected","lessThan":"d0bb592fa9def2bace90ac8926c0a1d6fa8c1aa0","versionType":"git"},{"version":"9a53c3a783c2fa9b969628e65695c11c3e51e673","status":"affected","lessThan":"8cafcb881364af5ef3a8b9fed4db254054033d8a","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/fat/namei_msdos.c","fs/fat/namei_vfat.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.19","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.19","versionType":"semver"},{"version":"5.10.252","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.202","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.165","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.128","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.75","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.14","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.4","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/fat/namei_msdos.c","fs/fat/namei_vfat.c"]}],"references":["https://git.kernel.org/stable/c/7fe0de287e931e07cb96ecf1f449b2ebdb0e1115","https://git.kernel.org/stable/c/9894c79fd9466612d0514be157b5c30cd93aa645","https://git.kernel.org/stable/c/cd569b87378b9c33ae13c23d6bb9d205d66f7c4b","https://git.kernel.org/stable/c/d3b7ffa90f613938128432c7b2f35b7aa4bdd86b","https://git.kernel.org/stable/c/955c5d670b5ae07c78f4345e23a895638db96ce1","https://git.kernel.org/stable/c/17866f8a0822d414cb02e621cf003a7d04396ef8","https://git.kernel.org/stable/c/d0bb592fa9def2bace90ac8926c0a1d6fa8c1aa0","https://git.kernel.org/stable/c/8cafcb881364af5ef3a8b9fed4db254054033d8a"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:07.131Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/45xxx/CVE-2026-45915.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-45915","state":"PUBLISHED","datePublished":"2026-05-27T12:17:30.699Z","dateUpdated":"2026-05-27T12:17:30.699Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-05-13T15:03:33.085Z"},"containers":{"cna":{"title":"fat: avoid parent link count underflow in rmdir","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nfat: avoid parent link count underflow in rmdir\n\nCorrupted FAT images can leave a directory inode with an incorrect\ni_nlink (e.g. 2 even though subdirectories exist). rmdir then\nunconditionally calls drop_nlink(dir) and can drive i_nlink to 0,\ntriggering the WARN_ON in drop_nlink().\n\nAdd a sanity check in vfat_rmdir() and msdos_rmdir(): only drop the\nparent link count when it is at least 3, otherwise report a filesystem\nerror."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"9a53c3a783c2fa9b969628e65695c11c3e51e673","status":"affected","lessThan":"7fe0de287e931e07cb96ecf1f449b2ebdb0e1115","versionType":"git"},{"version":"9a53c3a783c2fa9b969628e65695c11c3e51e673","status":"affected","lessThan":"9894c79fd9466612d0514be157b5c30cd93aa645","versionType":"git"},{"version":"9a53c3a783c2fa9b969628e65695c11c3e51e673","status":"affected","lessThan":"cd569b87378b9c33ae13c23d6bb9d205d66f7c4b","versionType":"git"},{"version":"9a53c3a783c2fa9b969628e65695c11c3e51e673","status":"affected","lessThan":"d3b7ffa90f613938128432c7b2f35b7aa4bdd86b","versionType":"git"},{"version":"9a53c3a783c2fa9b969628e65695c11c3e51e673","status":"affected","lessThan":"955c5d670b5ae07c78f4345e23a895638db96ce1","versionType":"git"},{"version":"9a53c3a783c2fa9b969628e65695c11c3e51e673","status":"affected","lessThan":"17866f8a0822d414cb02e621cf003a7d04396ef8","versionType":"git"},{"version":"9a53c3a783c2fa9b969628e65695c11c3e51e673","status":"affected","lessThan":"d0bb592fa9def2bace90ac8926c0a1d6fa8c1aa0","versionType":"git"},{"version":"9a53c3a783c2fa9b969628e65695c11c3e51e673","status":"affected","lessThan":"8cafcb881364af5ef3a8b9fed4db254054033d8a","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/fat/namei_msdos.c","fs/fat/namei_vfat.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.19","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.19","versionType":"semver"},{"version":"5.10.252","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.202","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.165","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.128","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.75","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.14","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.4","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/fat/namei_msdos.c","fs/fat/namei_vfat.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/7fe0de287e931e07cb96ecf1f449b2ebdb0e1115"},{"url":"https://git.kernel.org/stable/c/9894c79fd9466612d0514be157b5c30cd93aa645"},{"url":"https://git.kernel.org/stable/c/cd569b87378b9c33ae13c23d6bb9d205d66f7c4b"},{"url":"https://git.kernel.org/stable/c/d3b7ffa90f613938128432c7b2f35b7aa4bdd86b"},{"url":"https://git.kernel.org/stable/c/955c5d670b5ae07c78f4345e23a895638db96ce1"},{"url":"https://git.kernel.org/stable/c/17866f8a0822d414cb02e621cf003a7d04396ef8"},{"url":"https://git.kernel.org/stable/c/d0bb592fa9def2bace90ac8926c0a1d6fa8c1aa0"},{"url":"https://git.kernel.org/stable/c/8cafcb881364af5ef3a8b9fed4db254054033d8a"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-27T12:17:30.699Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.19","versionEndExcluding":"5.10.252"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.19","versionEndExcluding":"5.15.202"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.19","versionEndExcluding":"6.1.165"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.19","versionEndExcluding":"6.6.128"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.19","versionEndExcluding":"6.12.75"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.19","versionEndExcluding":"6.18.14"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.19","versionEndExcluding":"6.19.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.19","versionEndExcluding":"7.0"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}