CVE-2022-48864 in Linux
Summary
by MITRE • 07/16/2024
In the Linux kernel, the following vulnerability has been resolved:
vdpa/mlx5: add validation for VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET command
When control vq receives a VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET command request from the driver, presently there is no validation against the number of queue pairs to configure, or even if multiqueue had been negotiated or not is unverified. This may lead to kernel panic due to uninitialized resource for the queues were there any bogus request sent down by untrusted driver. Tie up the loose ends there.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 07/23/2024
The vulnerability identified as CVE-2022-48864 resides within the Linux kernel's virtual data path acceleration implementation, specifically affecting the mlx5 driver component. This issue manifests in the handling of virtio network control commands, where the kernel fails to properly validate incoming requests from virtualized network drivers. The vulnerability is particularly concerning as it affects the virtualized networking stack that many cloud environments and virtualization platforms depend upon for network performance and isolation. When a malicious or improperly configured driver sends a VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET command to the control virtqueue, the kernel processes this without adequate validation checks, creating a potential pathway for system instability and denial of service conditions.
The technical flaw stems from insufficient input validation within the mlx5 driver's control queue processing logic. Specifically, the kernel does not verify whether the requested number of queue pairs is within acceptable limits or whether multiqueue functionality has been properly negotiated between the driver and the hypervisor. This lack of validation means that an untrusted or compromised driver could send malformed requests containing excessive queue pair counts or attempt to configure queues without proper negotiation. The absence of these validation checks leads to the kernel attempting to initialize resources for queue pairs that may not exist or are beyond the system's capacity, resulting in memory corruption and potentially triggering a kernel panic. This vulnerability directly maps to CWE-129, which addresses insufficient validation of length of input buffers, and CWE-131, which covers improper handling of length parameter values.
The operational impact of this vulnerability extends beyond simple denial of service to potentially compromise the stability and security of virtualized environments. In cloud computing deployments where multiple tenants share the same physical hardware, an attacker controlling a guest virtual machine could exploit this vulnerability to crash the host kernel, disrupting services for other virtual machines running on the same system. The vulnerability affects systems using Mellanox ConnectX series network adapters with VDPA (Virtual Data Path Acceleration) support, which are commonly found in enterprise data centers and cloud infrastructure. Attackers could leverage this weakness to perform persistent denial of service attacks against virtualized network services, potentially leading to complete system crashes or requiring manual intervention to restore service. The vulnerability's exploitation does not require elevated privileges within the guest operating system, making it particularly dangerous in multi-tenant environments where guest isolation is paramount.
Mitigation strategies for CVE-2022-48864 focus on applying the official kernel patches that introduce proper validation checks for the VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET command. System administrators should prioritize updating their Linux kernel versions to include the fix, which typically involves validating the number of queue pairs against the maximum supported configuration and ensuring that multiqueue negotiation has been properly established before processing any queue configuration requests. Organizations running virtualized environments should implement monitoring for unusual network control command patterns that might indicate exploitation attempts. The fix aligns with ATT&CK technique T1499.004, which covers network denial of service attacks, and represents a fundamental security improvement in kernel virtualization support. Additionally, implementing proper network segmentation and access controls within virtualized environments can help limit the potential impact of such vulnerabilities, while regular security audits of virtualization components should include verification of kernel patch levels and proper configuration of virtualized network resources.