{"id":"CVE-2026-90277","summary":"md/md-llbitmap: prevent create failure bitmap UAF","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nmd/md-llbitmap: prevent create failure bitmap UAF\n\nllbitmap_create() publishes mddev-\u003ebitmap before reading the bitmap\nsuperblock. This is needed because llbitmap_read_sb() can initialize a\nnew bitmap and flush it through helpers that use mddev-\u003ebitmap.\n\nIf llbitmap_read_sb() fails, the old cleanup dropped bitmap_info.mutex\nand freed llbitmap before clearing mddev-\u003ebitmap. Readers such as\n/proc/mdstat rely on bitmap_info.mutex to keep the bitmap pointer stable\nwhile collecting bitmap stats, so they could observe the stale pointer\nafter the failed create path released the mutex.\n\nClear mddev-\u003ebitmap while still holding bitmap_info.mutex, then free the\nfailed llbitmap after dropping the mutex. This makes mutex-protected\nreaders see either a live bitmap or no bitmap.","modified":"2026-09-19T03:47:28.843672278Z","published":"2026-09-17T16:08:09.328Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90277.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/2116c2f0a0e547615886900e2ed8c529c016499b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/2f0722435ce3a844dbb66b9bb0a18229dcc8739c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/930cc4f1af5a1afcd545a6ba00e38921ff8401e0"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90277.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-90277"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"5ab829f1971dc99f2aac10846c378e67fc875abc"},{"fixed":"930cc4f1af5a1afcd545a6ba00e38921ff8401e0"},{"fixed":"2f0722435ce3a844dbb66b9bb0a18229dcc8739c"},{"fixed":"2116c2f0a0e547615886900e2ed8c529c016499b"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-90277.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.18.0"},{"fixed":"6.18.52"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.6"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-90277.json"}}],"schema_version":"1.9.0"}