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CVE-2026-63848
drm/amdgpu/jpeg: set no_user_fence for JPEG v2.0 ring
Published 2026-07-19 (3 months ago) by the Linux kernel CNA. Subsystem drivers/gpu. Debian urgency: not yet assigned.
What to do, per Debian release
Debian's own status for CVE-2026-63848 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 | vulnerable | 6.1.190-1 | No fix published anywhere yet, neither in Debian nor upstream for the series bookworm tracks. Watch the Debian tracker page for this CVE. Advisories for bookworm have historically landed a median of 23 days after publication. |
| Debian 13trixie | fixed | 6.12.94-1 | Update the kernel and reboot. Fixed in 6.12.94-1. A running kernel keeps the old code until the machine restarts. |
| Debian 14forky | fixed | 7.0.10-1 | Update the kernel and reboot. Fixed in 7.0.10-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.0.10-1 | Update the kernel and reboot. Fixed in 7.0.10-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
JPEG rings do not support 64-bit user fence writes, reject CS submissions with user fences. (cherry picked from commit 96179da0c6b059eb31706a0abe8dd6381c533143)
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/amd/amdgpu/jpeg_v2_0.c
- What this is
- RADEON and AMDGPU DRM DRIVERSMAINTAINERS section matched on drivers/gpu/drm/amd/ · amd-gfx@lists.freedesktop.org · Supported
- Kernel module
- amdgpu
Check it on the machine
grep -w CONFIG_DRM_AMDGPU /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 amdgpuPrints 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 builds this, but not on every flavour. At least one release below builds the code on some of its kernel flavours and not on others, so the answer depends on the architecture and flavour installed.
- bookwormMnot built on amd64/cloud-amd64, arm64/cloud-arm64, armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp
- trixieMnot built on amd64/cloud-amd64, arm64/cloud-arm64, armel/rpi, armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp, s390x/s390x
- forky, sidMnot built on amd64/cloud-amd64, arm64/cloud-arm64, s390x/s390x
- M
- a module where it is built at all; some flavours do not build it
- Build switch
- CONFIG_DRM_AMDGPU
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
- 0.18%, higher than 6.6% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- not yet assignedsource
- 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 |
|---|---|---|
| 5.6 | 6.6.141 | f675801889b2 |
| 5.6 | 6.12.91 | 2e216c2ff159 |
| 5.6 | 6.18.33 | b41248d1c183 |
| 5.6 | 7.0.10 | 41c4f3f68a34 |
| 5.6 | 7.1 | e5f612dc9165 |
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 vulnerable code is reached only through DRM_IOCTL_AMDGPU_CS on an AMDGPU render node (/dev/dri/renderD*), requiring a local ioctl to submit a command buffer with AMDGPU_CHUNK_ID_FENCE to the JPEG v2.0 decode ring (AMDGPU_HW_IP_VCN_JPEG).
- AC:LAttack complexity, low
- On affected VCN 2.0.x hardware with JPEG v2.0 (e.g. Navi/Vega20), an attacker fully controls CS submission parameters and can reliably trigger the unsupported 64-bit user fence path without races or conditions beyond attacker control.
- PR:LPrivileges required, low
- DRM_IOCTL_AMDGPU_CS is gated by DRM_AUTH|DRM_RENDER_ALLOW, so any unprivileged local user with render-node access (typically render/video group membership) can reach the vulnerable path without root or init-namespace capabilities.
- UI:NUser interaction, none
- Exploitation requires only programmatic ioctl submission by the attacker; no victim interaction such as opening files, mounting filesystems, or clicking prompts is needed.
- S:UScope, unchanged
- The flaw enables GPU-initiated memory corruption within the attacker's own AMDGPU context/VM via the render node, which is a standard local kernel/GPU-driver privilege boundary rather than a cross-authority escape such as VM guest-to-host or IOMMU bypass.
- C:HConfidentiality impact, high
- Submitting a 64-bit user fence to a JPEG ring that only supports 32-bit fence writes causes the hardware to perform misdirected or out-of-bounds GPU memory writes, providing a memory-corruption primitive that can be leveraged for information disclosure.
- I:HIntegrity impact, high
- The unsupported fence write gives the attacker a GPU-initiated arbitrary-write primitive at attacker-chosen GPU virtual addresses within their VM mappings, which is memory corruption exploitable for further integrity compromise or code execution.
- A:HAvailability impact, high
- Incorrect fence handling on the JPEG decode ring can hang or fault the GPU, trigger driver error-recovery paths, and cause system-wide graphics disruption or kernel oops, constituting high availability impact.