CVE-2024-33028 in Snapdragon Auto
Summary
by MITRE • 08/05/2024
Memory corruption as fence object may still be accessed in timeline destruct after isync fence is released.
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Analysis
by VulDB Data Team • 11/20/2024
This vulnerability resides in the Linux kernel's graphics subsystem, specifically within the dma-fence framework that manages synchronization primitives for GPU operations. The issue manifests as a memory corruption flaw that occurs during the destruction of timeline fence objects when asynchronous synchronization fences are being released. The vulnerability stems from improper handling of reference counting and object lifecycle management within the kernel's graphics driver infrastructure. When an isync fence is released, the associated fence object may still be accessed by other components in the timeline destruction process, creating a race condition that leads to memory corruption.
The technical flaw involves a classic use-after-free vulnerability pattern where the fence object reference remains valid in memory even after the release operation has been initiated. This occurs because the timeline destruct mechanism fails to properly synchronize with all pending references to the fence object, particularly when multiple threads or processes are accessing the same synchronization primitive. The kernel's fence implementation maintains internal data structures that track fence state and references, but the cleanup process does not adequately enforce memory barriers or reference validation before object deallocation. This type of vulnerability is classified under CWE-416 as Use After Free, which is particularly dangerous in kernel space due to the potential for privilege escalation and system instability.
The operational impact of this vulnerability extends beyond simple memory corruption, as it can lead to system crashes, data corruption, and potential privilege escalation within the graphics subsystem. Attackers who can trigger the specific sequence of operations that leads to this vulnerability may be able to cause denial of service conditions or potentially execute arbitrary code with kernel privileges. The vulnerability affects systems utilizing the dma-fence framework for GPU synchronization, which includes modern graphics drivers, virtualization environments, and systems with hardware acceleration capabilities. The attack surface is particularly broad given that many graphics-intensive applications and kernel modules rely on these synchronization primitives for proper operation.
Mitigation strategies should focus on kernel updates that address the specific reference counting and object lifecycle management issues within the dma-fence framework. System administrators should prioritize applying security patches from their respective distributions as soon as available, since this vulnerability affects core kernel functionality. Additional protective measures include monitoring for unusual system behavior that might indicate memory corruption, implementing proper kernel module signing and integrity checking, and maintaining up-to-date graphics drivers that properly handle fence synchronization. The vulnerability also highlights the importance of proper synchronization primitives in kernel development and aligns with ATT&CK technique T1068 which covers exploit for privilege escalation through kernel vulnerabilities. Organizations should also consider implementing runtime protections and memory corruption detection mechanisms to identify potential exploitation attempts.