The CVE-2026-68260 patch locks pvr_vm_map(), but this treats a symptom. The real problem: drm_gpuvm exposes find() and map/unmap() as independent operations whose safety depends entirely on callers independently acquiring vm_ctx->lock—a lock that lives outside the core subsystem's API contract. The driver must know, entirely from external knowledge, that every find() call must be preceded by a lock the core API never demands. This is a classic violation of interface design: the contract should make correct usage natural and incorrect usage difficult. Instead, we have a subsystem where safe and unsafe paths look identical until a race window opens during specific interleaving. The null dereference at offset 0x10 into a GPUVA structure during find() indicates map/unmap tears down the data structure mid-iteration—a race that could have integrity consequences beyond kernel panic. The fix applied to pvr_vm_map() makes that call path safe, but the architecture remains unchanged. Any other driver calling map/unmap without acquiring vm_ctx->lock will hit the same race, and notably, their unsafe map/unmap can corrupt find() operations from drivers that ARE properly locking. The narrow race window explains why this went undetected—developers tested, found it worked, and shipped. The question is how many other DRM drivers using drm_gpuvm have not acquired vm_ctx->lock before map/unmap. The answer is likely "most of them, some haven't hit the window yet." Treat this less as a PowerVR bug and more as evidence that drm_gpuvm needs mandatory internal locking or a compiler-verifiable protocol.
CVE-2026-68260
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedIn the Linux kernel, the following vulnerability has been resolved: drm/imagination: acquire vm_ctx->lock before mapping memory to GPU VM The drm gpuvm code doesn't protect find operation against map operation, and the driver needs to ensure a map operation shouldn't happen when a find operation is in progress. In some cases a find operation will be in progress when doing map/unmap operations, and the find operation will do a NULL pointer dereference. An example of the stack trace of such NULL dereference is shown below: ``` Unable to handle kernel access to user memory without uaccess routines at virtual address 0000000000000010 [<ffffffff01e989d4>] drm_gpuva_find+0x28/0x6c [drm_gpuvm] [<ffffffff01ed3a40>] pvr_vm_unmap+0x34/0x68 [powervr] [<ffffffff01ec69da>] pvr_ioctl_vm_unmap+0x2e/0x50 [powervr] [<ffffffff8080ce0a>] drm_ioctl_kernel+0x8e/0xdc [<ffffffff8080d016>] drm_ioctl+0x1be/0x3e0 [<ffffffff802bec3e>] __riscv_sys_ioctl+0xba/0xc4 [<ffffffff80d858b2>] do_trap_ecall_u+0x23e/0x3f4 [<ffffffff80d92288>] handle_exception+0x168/0x174 ``` As all occurences of drm_gpuva_find*() are already guarded by vm_ctx->lock, make pvr_vm_map() to acquire this lock to prevent disturbing any find operation. This fixes the NULL deference problem in drm_gpuva_find*().
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysisA detailed technical summary for this CVE is being prepared.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Local
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataThere is no version to upgrade to and no patch to apply. Every affected install stays exposed until the vendor ships a fix — or somebody else builds one.
Free. We build fixes in the order the community asks for them — and we’ll tell you the moment this one lands.
We develop and verify an original fix where the vendor hasn’t, from $1,950. Deployed to your staging first — never straight to production.
Scope it with usSee what else the community needs solved on the solutions-needed board.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-68260 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesThe CVE-2026-68260 patch locks pvr_vm_map(), but this treats a symptom. The real problem: drm_gpuvm exposes find() and map/unmap() as independent operations whose safety depends entirely on callers independently acquiring vm_ctx->lock—a lock that lives outside the core subsystem's API contract. The driver must know, entirely from external knowledge, that every find() call must be preceded by a lock the core API never demands. This is a classic violation of interface design: the contract should make correct usage natural and incorrect usage difficult. Instead, we have a subsystem where safe and unsafe paths look identical until a race window opens during specific interleaving. The null dereference at offset 0x10 into a GPUVA structure during find() indicates map/unmap tears down the data structure mid-iteration—a race that could have integrity consequences beyond kernel panic. The fix applied to pvr_vm_map() makes that call path safe, but the architecture remains unchanged. Any other driver calling map/unmap without acquiring vm_ctx->lock will hit the same race, and notably, their unsafe map/unmap can corrupt find() operations from drivers that ARE properly locking. The narrow race window explains why this went undetected—developers tested, found it worked, and shipped. The question is how many other DRM drivers using drm_gpuvm have not acquired vm_ctx->lock before map/unmap. The answer is likely "most of them, some haven't hit the window yet." Treat this less as a PowerVR bug and more as evidence that drm_gpuvm needs mandatory internal locking or a compiler-verifiable protocol.
Practitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-68260 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data