{"id":"CVE-2026-90277","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nmd/md-llbitmap: prevent create failure bitmap UAF\n\nllbitmap_create() publishes mddev->bitmap before reading the bitmap\nsuperblock","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nmd/md-llbitmap: prevent create failure bitmap UAF\n\nllbitmap_create() publishes mddev->bitmap before reading the bitmap\nsuperblock. This is needed because llbitmap_read_…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 5ab829f1971dc99f2aac10846c378e67fc875abc < 930cc4f1af5a1afcd545a6ba00e38921ff8401e0","Linux >= 5ab829f1971dc99f2aac10846c378e67fc875abc < 2f0722435ce3a844dbb66b9bb0a18229dcc8739c","Linux >= 5ab829f1971dc99f2aac10846c378e67fc875abc < 2116c2f0a0e547615886900e2ed8c529c016499b","Linux 6.18"],"published":"2026-09-17","updated":"2026-09-17","sourceUpdated":"2026-09-17T17:17:24.353","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-90277","references":[{"url":"https://git.kernel.org/stable/c/2116c2f0a0e547615886900e2ed8c529c016499b","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/2f0722435ce3a844dbb66b9bb0a18229dcc8739c","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/930cc4f1af5a1afcd545a6ba00e38921ff8401e0","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-09-17T16:21:47.836Z","epss":0.00198,"epssPercentile":0.09831,"slug":"CVE-2026-90277","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nmd/md-llbitmap: prevent create failure bitmap UAF\n\nllbitmap_create() publishes mddev->bitmap 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->bitmap.\n\nIf llbitmap_read_sb() fails, the old cleanup dropped bitmap_info.mutex\nand freed llbitmap before clearing mddev->bitmap. 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->bitmap 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}