CVE-2019-12615 in Linux
Summary
by MITRE
An issue was discovered in get_vdev_port_node_info in arch/sparc/kernel/mdesc.c in the Linux kernel through 5.1.6. There is an unchecked kstrdup_const of node_info->vdev_port.name, which might allow an attacker to cause a denial of service (NULL pointer dereference and system crash).
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Analysis
by VulDB Data Team • 09/26/2023
The vulnerability identified as CVE-2019-12615 resides within the Linux kernel's SPARC architecture implementation, specifically in the mdesc.c file where the get_vdev_port_node_info function processes device node information. This issue represents a classic null pointer dereference vulnerability that can be exploited to cause system instability and potential denial of service conditions. The flaw manifests when the kernel attempts to handle virtual device port information during system initialization or device enumeration processes on SPARC-based systems.
The technical root cause of this vulnerability stems from an unchecked kstrdup_const operation performed on node_info->vdev_port.name without proper validation of the source data. The kstrdup_const function is designed to duplicate strings and allocate kernel memory for string storage, but it does not perform null checks on the input parameter. When the vdev_port.name field contains invalid or unexpected data, particularly null values, the subsequent memory allocation and processing can lead to a NULL pointer dereference. This type of vulnerability falls under CWE-476 which specifically addresses NULL pointer dereference conditions in software implementations.
The operational impact of CVE-2019-12615 extends beyond simple denial of service to potentially compromise system stability and availability. An attacker who can manipulate the device node information or trigger specific hardware enumeration sequences could cause the kernel to crash and reboot the system, effectively creating a denial of service condition that could be exploited in various attack scenarios. The vulnerability affects Linux kernel versions through 5.1.6, representing a significant window of affected systems that would require immediate patching or mitigation strategies. This vulnerability particularly impacts SPARC architecture systems where the mdesc (machine description) subsystem is actively used for device tree parsing and hardware configuration.
From a security framework perspective, this vulnerability aligns with ATT&CK technique T1499.004 which involves network denial of service attacks through system resource exhaustion or kernel exploitation. The vulnerability demonstrates a critical flaw in kernel memory management and input validation processes that could be leveraged by attackers to disrupt system operations. Organizations running SPARC-based Linux systems should prioritize patching this vulnerability as it represents a direct threat to system availability and stability. The remediation strategy involves applying the appropriate kernel patches that implement proper null checking before the kstrdup_const operation, ensuring that any potentially malformed device node information does not lead to system crashes. Additionally, system administrators should monitor for any unusual device enumeration patterns or kernel oops messages that might indicate exploitation attempts against this vulnerability.