CVE-2026-93823 drm/amdkfd: Let driver decide buffer size at AMDKFD_IOC_GET_DMABUF_INFO ioctl
A local attacker with render-group access can trigger a kernel out-of-memory condition via the AMDKFD_IOC_GET_DMABUF_INFO ioctl by specifying a large buffer size.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-93823?
CVE-2026-93823 is a denial of service vulnerability in Linux, published on 24 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
drm/amdkfd: Let driver decide buffer size at AMDKFD_IOC_GET_DMABUF_INFO ioctl
amdkfd driver needs allocate buffer to return bo metadata to user space. The buffer size is controlled by user currently. It is a potential security issue that hostile value (e.g. 2 GiB) lets any render-group user trigger order-MAX allocation/OOM in kernel context.
This patch first finds bo metadata size. If the size is smaller than user provided value drive can safely allocate buffer in kernel space and copy to user space buffer. If not, driver will let user know, not allocate and copy. User will redo with new buffer in user space.
This patch lets driver decide buffer allocation size to avoid potential hostile size from user space.
(cherry picked from commit f54ce9e8cbd3abe0eda3a285f54dc4f572fe589a)
Which versions are affected by CVE-2026-93823?
How do I fix CVE-2026-93823?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-93823 being exploited?
There is no known exploitation of CVE-2026-93823 in the wild and no public exploit code.
Sources
Also known as AZL-103685, BELL-CVE-2026-93823, DEBIAN-CVE-2026-93823, GHSA-qq85-p63r-6hwh, UBUNTU-CVE-2026-93823.