CVE-2026-89801

HIGH
Published Sep 16, 2026 Modified Sep 16, 2026

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 must be NULL on submit failure. This frees a live region on an unrelated failure, reachable single-job when drm_gpuvm_sm_unmap_ops_create() returns -ENOMEM; if another job owns the same region, its cleanup then removes and puts the freed region, a use-after-free. Clear op->reg on both failure paths.

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CVSS v3.1 Score

7.8
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References

Frequently Asked Questions

What is CVE-2026-89801? +
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 must be NULL on submit failure. This frees a live region on an unrelated failure, reachable single-job when drm_gpuvm_sm_unmap_ops_create() returns -ENOMEM; if another job owns the same region, its cleanup then removes and puts the freed region, a use-after-free. Clear op->reg on both failure paths. It has a CVSS v3.1 base score of 7.8 (HIGH).
How severe is CVE-2026-89801? +
CVE-2026-89801 has a CVSS v3.1 score of 7.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.
How do I check if I'm vulnerable to CVE-2026-89801? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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