fix: the dma proxy driver passes user-supplied physi... in dmaproxy.c

[orbisai0security]

Summary

Fix critical severity security issue in microblaze/dmaproxy/dmaproxy.c.

Vulnerability

Field	Value
ID	V-010
Severity	CRITICAL
Scanner	multi_agent_ai
Rule	V-010
File	microblaze/dmaproxy/dmaproxy.c:258

Description: The DMA proxy driver passes user-supplied physical memory addresses (um->addr[0] and um->addr[1]) directly to the DMA engine without any validation. A local attacker with access to the dmaproxy device node can supply arbitrary physical addresses, directing the DMA hardware to read from or write to any location in physical memory — including kernel code, credential structures, and hardware registers. This attack bypasses all software-based memory protections including SMEP, SMAP, and KASLR because the DMA engine operates at the hardware level, outside the CPU's memory protection mechanisms.

Changes

• microblaze/dmaproxy/dmaproxy.c

Verification

• Build passes
• Scanner re-scan confirms fix
• LLM code review passed

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Automated security fix by OrbisAI Security