CVE-2022-49019 in Linux
Summary
by MITRE • 10/21/2024
In the Linux kernel, the following vulnerability has been resolved:
net: ethernet: nixge: fix NULL dereference
In function nixge_hw_dma_bd_release() dereference of NULL pointer priv->rx_bd_v is possible for the case of its allocation failure in nixge_hw_dma_bd_init().
Move for() loop with priv->rx_bd_v dereference under the check for its validity.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
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Analysis
by VulDB Data Team • 01/19/2026
The vulnerability identified as CVE-2022-49019 represents a critical null pointer dereference flaw within the Linux kernel's networking subsystem, specifically affecting the NIXGE (NXP i.MX6 Ultra Lite Gigabit Ethernet) driver implementation. This issue manifests in the nixge_hw_dma_bd_release() function where the kernel attempts to dereference a pointer variable priv->rx_bd_v without first verifying whether the memory allocation for this structure succeeded. The flaw occurs in a specific code path where the driver's initialization routine nixge_hw_dma_bd_init() fails to allocate the required receive buffer descriptors, leaving the priv->rx_bd_v pointer in a null state. When the cleanup function nixge_hw_dma_bd_release() is subsequently invoked, it proceeds to iterate through the receive buffer descriptors without validating the pointer's validity, leading to a kernel panic or system crash. This type of vulnerability falls under the CWE-476 category of NULL Pointer Dereference, which is a fundamental programming error that can result in complete system compromise.
The operational impact of this vulnerability extends beyond simple system instability, as it creates a potential attack vector for malicious actors who could exploit this condition to cause denial of service or system crashes in embedded systems utilizing NXP i.MX6 Ultra Lite SoCs. The NIXGE driver is commonly found in industrial embedded devices, automotive systems, and IoT platforms where reliable network connectivity is critical. The vulnerability was discovered through systematic kernel verification conducted by the Linux Verification Center using SVACE static analysis tools, highlighting the importance of automated verification in identifying memory management flaws. This finding demonstrates how seemingly simple pointer validation issues can have significant implications in real-time embedded systems where network reliability is paramount. The flaw specifically affects systems running Linux kernels with the NIXGE driver enabled, particularly those deployed in industrial automation, network infrastructure equipment, and automotive networking applications.
Mitigation strategies for CVE-2022-49019 involve implementing proper null pointer validation before dereferencing any dynamically allocated memory structures. The fix requires moving the for loop that processes the receive buffer descriptors to occur only after verifying that priv->rx_bd_v is not NULL, effectively preventing the kernel from attempting to access invalid memory addresses. System administrators should ensure that all affected Linux kernel versions are updated to patches containing the proper validation logic, which typically involves modifying the nixge_hw_dma_bd_release() function to include a conditional check before proceeding with buffer descriptor processing. Organizations deploying embedded systems with NXP i.MX6 Ultra Lite processors should conduct thorough vulnerability assessments to identify all instances of the affected driver and ensure proper patch management protocols are in place. This vulnerability aligns with ATT&CK technique T1499.004 for Network Denial of Service and represents a classic example of how improper error handling in kernel drivers can create exploitable conditions that compromise system integrity and availability. The fix demonstrates the importance of defensive programming practices in kernel space code where memory allocation failures must always be properly handled to prevent system crashes and maintain operational reliability.