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.
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.
Metrics
Affected Vendors & Products
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Thu, 17 Sep 2026 16:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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. | |
| Title | md/md-llbitmap: prevent create failure bitmap UAF | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Projects
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MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-09-17T16:08:09.328Z
Reserved: 2026-09-11T19:38:34.797Z
Link: CVE-2026-90277
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-09-17T17:17:24.353
Modified: 2026-09-17T17:17:24.353
Link: CVE-2026-90277
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.