CVE-2026-74453 in Linux
Summary
by MITRE • 08/15/2026
In the Linux kernel, the following vulnerability has been resolved:
drm/vc4: Zero the tile state data array before each BIN job
The binner BO is a single 16MB buffer split into 512KB slots that are handed out to jobs at submission time and recycled as jobs complete, without ever being cleared. Each slot holds the job's Tile State Data Array (TSDA) at its start, followed by the tile allocation pool.
While the tile allocation pool is only walked by the render thread through branches the binner generated during the current job, the TSDA is the PTB's own per-tile bookkeeping and is consumed by the hardware itself. Although the kernel sets the "Auto-initialise Tile State Data Array" flag in the tile binning mode configuration, the PTB demonstrably still acts on stale tile state left by the slot's previous user: the binner ends up creating invalid command streams with invalid primitive streams and branches, which can cause GPU hangs as observed in [1][2].
Zero the TSDA when the job's binning slot is configured. This clears 48 bytes per tile (~24KB for a 1080p frame) in the submission path, and guarantees the PTB never sees another job's tile state.
The tile count is only checked for being non-zero today, so the 8-bit fields it comes from can describe a tile state array almost six times larger than the slot it has to live in. Bound it before the slot is handed out, since such size decides how much of the slot is left for the tile alloc pool.
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Analysis
by VulDB Data Team • 08/15/2026
The vulnerability exists within the linux kernel's vc4 graphics driver component where improper handling of tile state data arrays leads to potential gpu hangs and invalid command streams during binner job execution. This issue specifically affects the display subsystem's tile binning functionality where memory management practices create conditions for data contamination between successive job executions. The problem manifests through a fundamental flaw in memory initialization protocols within the graphics processing unit's memory allocation system.
The technical root cause involves the binner buffer object which operates as a 16mb memory pool divided into 512kb slots allocated to individual jobs during submission. Each slot contains two primary components: the Tile State Data Array (TSDA) positioned at the beginning and a subsequent tile allocation pool. While the tile allocation pool is properly managed through hardware-generated branches that only reference current job data, the TSDA maintains persistent state information that gets reused across different jobs without proper clearing. This creates a scenario where stale data from previous job executions contaminates the current processing pipeline.
The vulnerability demonstrates a critical failure in memory sanitization practices within the graphics driver's submission path where the kernel configuration flag "Auto-initialise Tile State Data Array" proves insufficient to prevent state leakage. Hardware behavior becomes unpredictable when processing commands containing invalid primitive streams and branches that result from contaminated tile state data. This contamination directly impacts the programmable texture binner's operation causing complete gpu hangs as documented in referenced cases.
The mitigation approach requires explicit zeroing of the TSDA array during job slot configuration, which involves clearing 48 bytes per tile or approximately 24kb for full hd resolution frames. This modification ensures that when jobs are submitted to the graphics processing unit, they always receive clean tile state data regardless of previous job execution contexts. The solution addresses the fundamental memory management gap in the vc4 driver's resource recycling mechanism.
The vulnerability classification aligns with cwe-691 which covers insufficient initialization of a resource and relates to att&ck technique T1547-001 for privilege escalation through system component manipulation. Additional security implications include potential denial of service conditions and data integrity issues in graphics processing workflows. The memory boundary checking enhancement addresses potential buffer overflows that could occur when tile counts exceed allocated slot capacity, preventing malicious exploitation through oversized tile state arrays that might otherwise consume excessive memory resources.
This vulnerability represents a significant concern for embedded systems and mobile devices relying on vc4 graphics hardware where resource constraints make proper memory management critical for system stability. The performance impact of the mitigation is minimal since it only affects the job submission path rather than runtime execution, making it suitable for production environments where reliability is paramount.