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CVE-2026-68260
drm/imagination: acquire vm_ctx->lock before mapping memory to GPU VM
Published 2026-08-10 (2 months ago) by the Linux kernel CNA. Subsystem drivers/gpu. Debian urgency: unimportant.
What to do, per Debian release
Debian's own status for CVE-2026-68260 in every release this site tracks, and what each one means in practice. Every status below is the one the Debian Security Team publishes for this CVE. source
| Release | Status | Version | What this means |
|---|---|---|---|
| Debian 12bookworm | not affected | 6.1.190-1 | Nothing to do. bookworm never shipped the vulnerable code. |
| Debian 13trixie | fixed | 6.12.101-1 | Update the kernel and reboot. Fixed in 6.12.101-1. A running kernel keeps the old code until the machine restarts. |
| Debian 14forky | fixed | 7.1.6-1 | Update the kernel and reboot. Fixed in 7.1.6-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.1.6-1 | Update the kernel and reboot. Fixed in 7.1.6-1. A running kernel keeps the old code until the machine restarts. |
| Debian 12bookworm · linux-6.12 | fixedDLA-4745-1 · 2026-08-18 · text | 6.12.101-1~deb12u1 | Update the kernel and reboot. DLA-4745-1 shipped the fix on 2026-08-18, in 6.12.101-1~deb12u1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
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*().
Where it lives
The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.
drivers/gpu/drm/imagination/pvr_vm.c
- What this is
- IMGTEC POWERVR DRM DRIVERMAINTAINERS section matched on drivers/gpu/drm/imagination/ · Supported
- Kernel module
- powervr
Check it on the machine
grep -w CONFIG_DRM_POWERVR /boot/config-$(uname -r)Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.
lsmod | grep -w powervrPrints a line if that module is loaded right now, and nothing if it is not. One that is not loaded can still be loaded later by anything that needs it.
Show whether Debian builds this, per release
Debian does not build this code in 2 releases. It does build it in 2 releases, so the answer depends on which release the machine runs. The build rule could not be established for 1 release, so nothing is claimed about those.
- bookworm?
- trixien
- forky, sidMnot built on amd64/amd64, amd64/cloud-amd64, amd64/rt-amd64, arm64/arm64, arm64/arm64-16k, arm64/cloud-arm64, arm64/rt-arm64, armhf/armmp, armhf/armmp-lpae, loong64/loong64, ppc64el/powerpc64le, ppc64el/powerpc64le-64k, s390x/s390x
- bookworm · linux-6.12n
- ?
- not established - no Makefile entry for the affected file
- n
- not enabled on any flavour - this release does not build the code
- M
- a module where it is built at all; some flavours do not build it
Where a release above reads "not established", no build rule for the affected file was found in that release's kernel tree. That is a gap in this lookup, not a finding that the code is absent.
- Build switch
- CONFIG_DRM_POWERVR
From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages
Signals
- Published
- 2026-08-10 (2 months ago)source
- CVSS
- 7.8 high
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsource recompute it - Attack vector
- local (AV:L)source
- EPSS
- 0.16%, higher than 5.2% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- unimportantsource
- Subsystem
- drivers/gpu
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 6.8 | 6.12.101 | 1f1f2618e44b |
| 6.8 | 6.18.42 | 6253bb56bb2e |
| 6.8 | 7.1.6 | 15f58d44c244 |
| 6.8 | 7.2 | 17e2030f3760 |
Debian advisories
| Advisory | Date | Shipped to | Debian |
|---|---|---|---|
| DLA-4745-1 | 2026-08-18 | bookworm 6.12.101-1~deb12u1 | tracker |
Why the CNA scored it this way
Quoted from the kernel CNA's own scoring file, word for word. A highlighted metric carries the most severe value CVSS v3.1 defines for it, which is what pushes the score up. source
- AV:LAttack vector, local
- Triggered through the DRM_IOCTL_PVR_VM_MAP/VM_UNMAP ioctls on the PowerVR render node (/dev/dri/renderD*), which requires local access to the device file; no network or physical path exists.
- AC:LAttack complexity, low
- The attacker owns both sides of the race, issuing concurrent VM_MAP and VM_UNMAP ioctls from two threads on the same fd and vm_ctx handle, and can retry indefinitely with attacker-chosen mapping layouts that force split/remap (free) paths.
- PR:LPrivileges required, low
- The ioctls are marked DRM_RENDER_ALLOW, so no DRM master, root, or capability is needed; any unprivileged process able to open the render node (world-accessible or graphics-group on Android/embedded PowerVR devices) can reach the code.
- UI:NUser interaction, none
- The attacker performs the entire sequence itself by opening the render node, creating a VM context and issuing concurrent map/unmap ioctls; no victim action is involved.
- S:UScope, unchanged
- The corruption stays within the kernel's own security authority on the affected host; no VM, IOMMU or sandbox boundary is crossed by the flaw itself.
- C:HConfidentiality impact, high
- The unlocked map path frees drm_gpuva objects via pvr_vm_gpuva_remap()/pvr_vm_gpuva_unmap() while a concurrent find returns them, yielding a use-after-free whose reclaimed contents the attacker can groom to read kernel memory; racing MMU updates can also leave GPU page tables mapping unintended pages.
- I:HIntegrity impact, high
- The same use-after-free plus unsynchronized rb interval-tree insert/remove gives attacker-influenced writes through a freed/corrupted structure, and the racing pvr_mmu_map/unmap operations can corrupt GPU page tables, which is leveragable into arbitrary memory modification.
- A:HAvailability impact, high
- The reported failure is an immediate kernel NULL pointer dereference in drm_gpuva_find(), and tree corruption or use-after-free reliably produces oopses, and the ioctl can be re-issued to crash the system at will.