CVE-2026-46215
HighCVSS 7.8Exploitation Probability (EPSS)
Low risk3th percentile - higher than 3% of all known CVEs
Summary
A race condition was found in the Linux kernel DRM driver in the change_handle function. During handle swap, a single object briefly had two IDR entries, allowing a concurrent gem_close to delete the object and leave a dangling handle, leading to a use-after-free.
Risk Assessment
A local attacker could exploit this vulnerability to escalate privileges or leak kernel memory, compromising system confidentiality and integrity.
Recommendation
Immediately update the Linux kernel to a version containing the fix (commit that sets the old handle to NULL before the prime operation to prevent the race).
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: drm: Set old handle to NULL before prime swap in change_handle There was a potential race condition in change_handle. The ioctl briefly had a single object with two idr entries; a concurrent gem_close could delete the object and remove one of the handles while leaving the other one dangling, which could subsequently be dereferenced for a use-after-free. To fix this, do the same dance that gem_close itself does. (f6cd7daecff5 drm: Release driver references to handle before making it available again) First idr_replace the old handle to NULL. Later, if the prime operations are successful, actually close it. create_tail required a similar dance to avoid a similar problem. (bd46cece51a3 drm/gem: Fix race in drm_gem_handle_create_tail()) It idr_allocs the new handle with NULL, then swaps in the correct object later to avoid races. We don't need to do that here, since the only operations that could race are drm_prime, and change_handle holds the prime lock for the entire duration. v2: cleanups of error paths