{"id":"CVE-2026-90277","published":"2026-09-17T17:17:24.353","lastModified":"2026-09-17T17:17:24.353","description":"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_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.","cvssScore":null,"cvssSeverity":null,"cvssVector":null,"cwes":[],"vendors":[],"products":[],"references":[{"url":"https://git.kernel.org/stable/c/2116c2f0a0e547615886900e2ed8c529c016499b","tags":[]},{"url":"https://git.kernel.org/stable/c/2f0722435ce3a844dbb66b9bb0a18229dcc8739c","tags":[]},{"url":"https://git.kernel.org/stable/c/930cc4f1af5a1afcd545a6ba00e38921ff8401e0","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":null}