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CVE-2024-46730
drm/amd/display: Ensure array index tg_inst won't be -1
Published 2024-09-18 (2 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-2024-46730 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 | 6.10.9-1 | Update the kernel and reboot. Fixed in 6.10.9-1. A running kernel keeps the old code until the machine restarts. |
| Debian 14forky | fixed | 6.10.9-1 | Update the kernel and reboot. Fixed in 6.10.9-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 6.10.9-1 | Update the kernel and reboot. Fixed in 6.10.9-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
[WHY & HOW] tg_inst will be a negative if timing_generator_count equals 0, which should be checked before used. This fixes 2 OVERRUN issues reported by Coverity.
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/display/dc/core/dc_resource.c
- What this is
- AMD DISPLAY COREMAINTAINERS section matched on drivers/gpu/drm/amd/display/ · amd-gfx@lists.freedesktop.org · Supported
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
- 2024-09-18 (2 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
- 0.23%, higher than 12.8% 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 |
|---|---|---|
| 4.15 | 6.6.158 | 15403445b873 |
| 4.15 | 6.10.9 | a64284b9e199 |
| 4.15 | 6.11 | 687fe329f18a |
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 modeset ioctls on /dev/dri/card* (DRM_IOCTL_MODE_ATOMIC / SETCRTC) via amdgpu_dm_atomic_check() → dc_state_add_stream() → resource_map_pool_resources(). No network or remote input reaches this path.
- AC:LAttack complexity, low
- Within an affected resource-pool configuration the negative index is taken deterministically on every stream-add whose pipe_idx exceeds timing_generator_count; there is no race to win and no memory-layout condition the attacker must guess, and the attacker chooses when to issue the modeset.
- PR:LPrivileges required, low
- A local unprivileged user with a DRM fd holding master — the ordinary case for a logged-in console/graphical session, an Android compositor client, or a kiosk display stack — can issue the atomic modeset; no capability check exists anywhere on the path from the ioctl to acquire_otg_master_pipe_for_stream().
- UI:NUser interaction, none
- The attacker performs the modeset/stream-add entirely on their own; no action by another user or administrator is required.
- S:UScope, unchanged
- The corruption and its consequences stay inside the kernel's amdgpu display driver under the same security authority; no VM, IOMMU, or sandbox boundary is crossed.
- C:HConfidentiality impact, high
- The −1 index reads pointers outside the intended arrays and installs them as wrongly-typed objects, so subsequent accesses read struct fields (funcs, inst, dc_context contents) at mismatched offsets from adjacent kernel objects, exposing kernel pointers and enabling further disclosure through the type-confused reads.
- I:HIntegrity impact, high
- stream_res.opp — actually a struct dpp * — is written through (opp->mpcc_disconnect_pending[] stores and mpc_tree_params list manipulation corrupt the DPP object), and both stream_res.tg->funcs and stream_res.opp->funcs are read from offsets holding non-vtable data, including gamma-LUT bytes supplied by userspace, giving an indirect call through attacker-influenced memory and thus a control-flow hijack primitive.
- A:HAvailability impact, high
- At minimum the wrongly-typed or NULL pointer is dereferenced and called through during pipe programming, producing an immediate kernel oops/panic in the display pipeline, repeatable at will by the local attacker.