adreno-a7xx-exploitation

name

adreno-a7xx-exploitation

description

How to exploit CVE-2025-21479 on Qualcomm Adreno A7xx GPUs to achieve kernel R/W via GPU SMMU takeover. Use this skill whenever the user mentions Adreno A7xx, GPU SMMU exploitation, SDS privilege bypass, kernel physical memory access, or wants to understand/reproduce the CVE-2025-21479 vulnerability chain. Also use when discussing GPU microcode bugs, IB level masking issues, or dirty pagetable pivots on Android devices with Snapdragon chipsets.

Adreno A7xx SDS→RB Privilege Bypass Exploitation

This skill guides you through exploiting CVE-2025-21479 on Qualcomm Adreno A7xx GPUs to achieve arbitrary kernel memory read/write via GPU SMMU takeover and dirty pagetable pivot.

Vulnerability Overview

CVE-2025-21479: A microcode logic bug in Adreno A7xx firmware where register $12 (IB level tracker) is masked with 0x3 instead of 0x7, causing Set Draw State (SDS) at IB4 to be misidentified as IB0 (kernel ringbuffer), allowing privileged CP packets from user-controlled SDS.

Key Facts

Aspect	Details
Affected	Qualcomm Adreno A7xx GPU firmware (pre-fix)
Primitive	Execute privileged CP packets from SDS
Outcome	Arbitrary kernel physical/virtual R/W, SELinux disable, root
Prerequisite	KGSL GPU context creation (normal app capability)
Devices	Samsung S23 and other Snapdragon A7xx devices

IB Level Masking Bug

The kernel maintains a ringbuffer (RB=IB0). Userspace submits IB1 via CP_INDIRECT_BUFFER, chaining to IB2/IB3. SDS is a special command stream: