Use-After-Free in Linux Kernel DMA Engine

Executive Summary

This is a use-after-free vulnerability in the Linux kernel's DMA engine subsystem. It occurs in the dma_release_channel() function where a channel device's reference count is checked after a call to dma_chan_put(). The issue is that dma_chan_put() can trigger dma_device_put(), which may release the last reference to the device and free it if the DMA provider is already gone. This creates a race condition where the device could be freed before the check is completed.

Useful 0 Not Useful 0

Detection Guidance

This vulnerability is specific to the Linux kernel's dmaengine subsystem and may not have direct network detection methods. System administrators should check kernel logs for DMA-related errors or crashes, particularly after channel release operations. Commands like dmesg or journalctl may show relevant errors. Kernel version checks can identify if the fix is applied.

Useful 0 Not Useful 0

Impact Analysis

This vulnerability could lead to system crashes, memory corruption, or privilege escalation if exploited. An attacker with local access might trigger the use-after-free condition to execute arbitrary code or cause denial-of-service conditions on affected systems running vulnerable Linux kernel versions.

Useful 0 Not Useful 0

Compliance Impact

This vulnerability does not directly affect compliance with GDPR, HIPAA, or similar standards as it is a low-level kernel memory management issue unrelated to data protection or privacy controls.

Useful 0 Not Useful 0

Mitigation Strategies

Update the Linux kernel to a patched version that includes the fix for this use-after-free issue. Monitor kernel logs for DMA-related errors. If immediate patching is not possible, consider disabling affected DMA channels if they are not critical to system operation.

Useful 0 Not Useful 0