CVE-2026-23133 in Linux
Summary
by MITRE • 02/14/2026
In the Linux kernel, the following vulnerability has been resolved:
wifi: ath10k: fix dma_free_coherent() pointer
dma_alloc_coherent() allocates a DMA mapped buffer and stores the addresses in XXX_unaligned fields. Those should be reused when freeing the buffer rather than the aligned addresses.
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Analysis
by VulDB Data Team • 03/18/2026
The vulnerability CVE-2026-23133 represents a critical memory management flaw in the Linux kernel's wireless networking subsystem, specifically affecting the ath10k driver used for Qualcomm-based Wi-Fi chips. This issue stems from improper handling of DMA (Direct Memory Access) buffer management during memory allocation and deallocation operations. The flaw occurs when the kernel allocates DMA-mapped memory using the dma_alloc_coherent() function, which internally manages both aligned and unaligned memory addresses for proper hardware access. The driver correctly stores the unaligned addresses in XXX_unaligned fields during allocation, but fails to utilize these stored addresses when freeing the memory through dma_free_coherent(). This mismanagement creates a fundamental mismatch between allocation and deallocation operations, leading to potential memory corruption and system instability.
The technical root cause of this vulnerability lies in the improper pointer management within the ath10k driver's DMA buffer handling code. When dma_alloc_coherent() is called, it allocates memory that must be accessible by DMA-capable hardware devices, requiring specific alignment and addressing schemes. The kernel's DMA subsystem maintains separate tracking of aligned and unaligned addresses to ensure proper hardware access patterns. However, the ath10k driver incorrectly uses aligned addresses for the freeing operation instead of the originally stored unaligned addresses, creating a mismatch that can result in memory being freed from incorrect locations. This flaw directly relates to CWE-415: Double Free and CWE-416: Use After Free, as improper memory management can lead to both types of memory corruption vulnerabilities. The issue manifests as a potential kernel memory corruption that could be exploited to cause system crashes or potentially enable privilege escalation.
The operational impact of this vulnerability extends beyond simple system instability to potentially compromise system security and reliability in wireless networking environments. When the ath10k driver encounters this flaw, it may cause kernel panics or system crashes during Wi-Fi operations, particularly during high-frequency data transfers or when multiple concurrent connections are active. The vulnerability affects all systems running Linux kernels with the affected ath10k driver, making it a widespread concern for wireless networking infrastructure. In practical terms, this could lead to denial of service attacks against wireless services, where adversaries could repeatedly trigger the memory corruption by forcing the driver to allocate and free DMA buffers in specific patterns. The vulnerability is particularly concerning in server environments or embedded systems that rely heavily on wireless connectivity, as it could be exploited to disrupt critical network services or potentially provide a foothold for more sophisticated attacks.
Mitigation strategies for this vulnerability should focus on applying the official kernel patches that correct the pointer management in the ath10k driver. System administrators should prioritize updating to kernel versions that include the fix, typically those containing the specific commit that addresses the DMA buffer handling issue. Organizations should implement comprehensive patch management procedures to ensure all wireless networking equipment receives the necessary updates promptly. Additionally, monitoring systems should be configured to detect unusual memory allocation patterns or kernel panics that might indicate exploitation attempts. The fix specifically addresses the improper reuse of DMA addresses by ensuring that the unaligned addresses stored during allocation are correctly utilized during deallocation, aligning with best practices for DMA memory management as outlined in the Linux kernel documentation and security guidelines. Organizations should also consider implementing network segmentation and access controls to limit potential attack vectors and reduce the impact of any successful exploitation attempts.