CVE-2026-63878 drm/amdgpu: check num_entries in GEM_OP GET_MAPPING_INFO
A local attacker can trigger a kernel panic or warning by supplying an oversized entry count to the amdgpu GEM operation, causing a denial of service.
- 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-2026-63878?
CVE-2026-63878 is a vulnerability in Linux, published on 19 Jul 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/amdgpu: check num_entries in GEM_OP GET_MAPPING_INFO
kvcalloc(args->num_entries, sizeof(*vm_entries), GFP_KERNEL) at amdgpu_gem.c:1050 uses the user-supplied num_entries directly without any upper bounds check. Since num_entries is a __u32 and sizeof(drm_amdgpu_gem_vm_entry) is 32 bytes, a large num_entries produces an allocation exceeding INT_MAX, triggering WARNING in __kvmalloc_node_noprof(), causing a kernel WARNING, TAINT_WARN, and panic on CONFIG_PANIC_ON_WARN=y systems.
Add a size bounds check before we invoke the kvzalloc() to reject oversized num_entries early with -EINVAL.
(cherry picked from commit 1fe7bf5457f6efd7be60b17e23163ba54341d73d)
Which versions are affected by CVE-2026-63878?
How do I fix CVE-2026-63878?
Apply the vendor's patch.
Is CVE-2026-63878 being exploited?
There is no known exploitation of CVE-2026-63878 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-63878, DEBIAN-CVE-2026-63878, GHSA-7q2q-cf6q-6c84, UBUNTU-CVE-2026-63878.