CVE-2026-89801

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

drm/nouveau/uvmm: fix premature region free on failed OP_UNMAP_SPARSE

In nouveau_uvmm_bind_job_submit()'s OP_UNMAP_SPARSE arm, op->reg is set

from nouveau_uvma_region_find(), which only looks the region up and takes

no reference; a region's sole reference is its membership in

uvmm->region_mt. Two failure paths leave op->reg set: the -ENOENT check

when the region is busy, and the drm_gpuvm_sm_unmap_ops_create() failure.

The sibling nouveau_uvmm_sm_unmap_prepare() failure just below clears

op->reg; these two do not.

unwind_continue steps back one op, so the failing op is skipped by the

unwind loop and its op->reg stays set. nouveau_uvmm_bind_job_cleanup()

then enters its if (op->reg) branch and calls nouveau_uvma_region_remove()

and nouveau_uvma_region_put() on it, dropping the tree's sole reference

and freeing a region this job never created. The comment above the

cleanup loop documents the broken invariant: op->reg

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References