Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: md/md-llbitmap: prevent create failure bitmap UAF llbitmap_create() publishes mddev->bitmap before reading the bitmap superblock. This is needed because llbitmap_read_sb() can initialize a new bitmap and flush it through helpers that use mddev->bitmap. If llbitmap_read_sb() fails, the old cleanup dropped bitmap_info.mutex and freed llbitmap before clearing mddev->bitmap. Readers such as /proc/mdstat rely on bitmap_info.mutex to keep the bitmap pointer stable while collecting bitmap stats, so they could observe the stale pointer after the failed create path released the mutex. Clear mddev->bitmap while still holding bitmap_info.mutex, then free the failed llbitmap after dropping the mutex. This makes mutex-protected readers see either a live bitmap or no bitmap.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 5ab829f1971dc99f2aac10846c378e67fc875abc before 930cc4f1af5a1afcd545a6ba00e38921ff8401e0; affected 5ab829f1971dc99f2aac10846c378e67fc875abc before 2f0722435ce3a844dbb66b9bb0a18229dcc8739c; affected 5ab829f1971dc99f2aac10846c378e67fc875abc before 2116c2f0a0e547615886900e2ed8c529c016499b |
| Linux / Linux | affected 6.18; unaffected 0 before 6.18; unaffected 6.18.52 through 6.18.*; unaffected 7.2.6 through 7.2.*; unaffected 7.3 through * |
CWE
No CWE identifiers supplied.