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CVE-2026-64008
accel/rocket: fix UAF via dangling GEM handle in create_bo
Published 2026-07-19 (3 months ago) by the Linux kernel CNA. Subsystem drivers/accel. Debian urgency: unimportant.
What to do, per Debian release
Debian's own status for CVE-2026-64008 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 | not affected | 6.12.113-1 | Nothing to do. trixie never shipped the vulnerable code. |
| Debian 14forky | fixed | 7.0.12-1 | Update the kernel and reboot. Fixed in 7.0.12-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.0.12-1 | Update the kernel and reboot. Fixed in 7.0.12-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
rocket_ioctl_create_bo() inserts a GEM handle into the file's IDR via drm_gem_handle_create() early on, then performs several operations that can fail (sgt allocation, drm_mm insert, iommu_map). If any fail after the handle is live, the error path calls drm_gem_shmem_object_free() which kfree's the object without removing the handle from the IDR. This leaves a dangling handle pointing to freed slab memory. Any subsequent ioctl using that handle (PREP_BO, FINI_BO, SUBMIT) calls drm_gem_object_lookup() and dereferences freed memory (UAF). Fix by moving drm_gem_handle_create() to after all fallible operations succeed, matching the pattern used by panfrost, lima, and etnaviv. Also fix drm_mm_insert_node_generic() whose return value was silently overwritten by iommu_map_sgtable() on the next line. Add the missing error check. [tomeu: Move handle creation to the very end]
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/accel/rocket/rocket_gem.c
- What this is
- DRM ACCEL DRIVER FOR ROCKCHIP NPUMAINTAINERS section matched on drivers/accel/rocket/ · dri-devel@lists.freedesktop.org · Supported
Check it on the machine
grep -wE 'CONFIG_DRM_ACCEL|CONFIG_DRM_ACCEL_ROCKET' /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.
Show whether Debian builds this, per release
Debian does not build this code in 2 releases. The build rule could not be established for 2 releases, so nothing is claimed about those.
- bookworm, trixie?
- forky, sidn
- ?
- not established - no Makefile entry for the affected file
- n
- not enabled on any flavour - this release does not build the code
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 switches
- CONFIG_DRM_ACCEL, CONFIG_DRM_ACCEL_ROCKET
- Reads as
- all on means the file is compiled; any one off means it is not.
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
- 2026-07-19 (3 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
- 0.17%, higher than 6.3% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- unimportantsource
- Subsystem
- drivers/accel
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 6.18 | 6.18.35 | 18abd88d19ea |
| 6.18 | 7.0.12 | 451f1ccbbdb7 |
| 6.18 | 7.1 | f706e6a4ce75 |
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
- The bug is reached only through DRM ioctls on the local /dev/accel/accel* character device; there is no network, adjacent-wireless, or physical bus path to rocket_ioctl_create_bo().
- AC:LAttack complexity, low
- An attacker fully controls both steps—forcing CREATE_BO to fail after handle insertion (e.g., by exhausting the per-fd IOMMU drm_mm aperture or triggering sgt/iommu_map errors) and then issuing PREP_BO/FINI_BO/SUBMIT with the returned dangling handle—without depending on external timing or victim state.
- PR:LPrivileges required, low
- All rocket ioctls are registered with DRM_IOCTL_DEF_DRV flags 0 (no DRM_ROOT_ONLY/DRM_AUTH/DRM_MASTER), requiring only the ability to open the accel device node, which is standard unprivileged local access on RK3588 edge-AI/embedded systems running ML workloads.
- UI:NUser interaction, none
- Exploitation requires no action from a separate victim; the attacker creates the dangling handle and triggers the UAF through their own ioctl sequence on a device they opened.
- S:UScope, unchanged
- Impact is kernel heap UAF leading to local privilege escalation or crash within the same kernel security authority; it is not a VM escape, IOMMU DMA-boundary bypass, or cross-hypervisor attack.
- C:HConfidentiality impact, high
- The dangling GEM handle causes use-after-free of a kmalloc'd rocket_gem_object; subsequent lookups dereference freed slab memory (resv, sgt, mm node fields), enabling arbitrary kernel memory read via heap grooming.
- I:HIntegrity impact, high
- UAF on the GEM object structure allows heap spraying to corrupt kernel metadata and control flow; the SUBMIT ioctl path further processes corrupted BO pointers for NPU job scheduling, supporting arbitrary write and code execution primitives.
- A:HAvailability impact, high
- UAF dereferences in PREP_BO/FINI_BO/SUBMIT reliably cause kernel oops/panic, and the dangling-handle condition is repeatable for sustained denial of service.