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CVE-2023-52586
drm/msm/dpu: Add mutex lock in control vblank irq
Published 2024-03-06 (3 years 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-2023-52586 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 | 6.7.7-1 | Update the kernel and reboot. Fixed in 6.7.7-1. A running kernel keeps the old code until the machine restarts. |
| Debian 14forky | fixed | 6.7.7-1 | Update the kernel and reboot. Fixed in 6.7.7-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 6.7.7-1 | Update the kernel and reboot. Fixed in 6.7.7-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
Add a mutex lock to control vblank irq to synchronize vblank enable/disable operations happening from different threads to prevent race conditions while registering/unregistering the vblank irq callback. v4: -Removed vblank_ctl_lock from dpu_encoder_virt, so it is only a parameter of dpu_encoder_phys. -Switch from atomic refcnt to a simple int counter as mutex has now been added v3: Mistakenly did not change wording in last version. It is done now. v2: Slightly changed wording of commit message Patchwork: https://patchwork.freedesktop.org/patch/571854/
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/msm/disp/dpu1/dpu_encoder.c
drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys.h
drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
- What this is
- DRM DRIVER for Qualcomm display hardwareMAINTAINERS section matched on drivers/gpu/drm/msm/ · linux-arm-msm@vger.kernel.org · Maintained
Show whether Debian builds this, per release
Not established. This site could not find the build rule for the affected file in the kernel trees Debian ships, so it has no answer about whether Debian compiles this code. Read that as unknown, never as absent.
- bookworm, trixie, forky, sid?
- ?
- not established - no Makefile entry for the affected file
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.
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
Signals
- Published
- 2024-03-06 (3 years 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 4.6% 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 |
|---|---|---|
| 4.19 | 6.7.4 | 14f109bf74dd |
| 4.19 | 6.8 | 45284ff733e4 |
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 through local DRM primary-node ioctls (DRM_IOCTL_WAIT_VBLANK / CRTC sequence and modeset/kickoff paths) into dpu_encoder_*_control_vblank_irq on Qualcomm MSM DPU hardware; there is no network or adjacent-protocol reachability.
- AC:LAttack complexity, low
- An attacker who can open the DRM card node can drive both sides of the race—concurrent WAIT_VBLANK enable/disable (queued via msm vblank work) and irq_control from atomic kickoff/idle-PC/stop—so success does not depend on conditions outside attacker control.
- PR:LPrivileges required, low
- WAIT_VBLANK and related sequence ioctls require only an open /dev/dri/cardN fd (no DRM_AUTH/MASTER/CAP_SYS_ADMIN), and DRM master for the modeset side is granted to the session/video-group user via logind without real root.
- UI:NUser interaction, none
- The attacker triggers both vblank and resource-control paths entirely through their own DRM ioctls and threads; no separate victim action is required.
- S:UScope, unchanged
- Impact remains within the host kernel’s security authority; this is a standard kernel race/UAF, not a VM escape, IOMMU bypass, or other cross-boundary scope change.
- C:HConfidentiality impact, high
- The race can leave a vblank IRQ callback registered with phys_enc after refcount hits zero and the encoder is later freed (destroy only kfree’s phys without guaranteed unregister), yielding a use-after-free read of attacker-reclaimable heap via the IRQ handler.
- I:HIntegrity impact, high
- The same dangling IRQ callback UAF on phys_enc is heap-sprayable and provides a write/control-flow hijack primitive once the freed object is reused, consistent with scoring use-after-free as High integrity impact.
- A:HAvailability impact, high
- Mismatched register/unregister also hits WARN_ON on double-register, NULL/stale dereferences in the IRQ callback, and kernel oops/panic on the dangling phys_enc path, fully disrupting availability.