Source: psirt@nvidia.com
NVIDIA distributions of Linux contain a vulnerability in nvdla_emu_task_submit, where unvalidated input may allow a local attacker to cause stack-based buffer overflow in kernel code, which may lead to escalation of privileges, compromised integrity and confidentiality, and denial of service.
NVIDIA GPU drivers on Linux systems are vulnerable to a stack-based buffer overflow, allowing a local attacker to gain privilege escalation, compromise data integrity and confidentiality, and cause a denial-of-service. Exploiting this vulnerability could lead to complete system compromise. This vulnerability stems from improper input validation within the nvdla_emu_task_submit function.
Step 1: Trigger Preparation: The attacker crafts a malicious input payload designed to overflow a buffer within the nvdla_emu_task_submit function. This payload is likely structured to overwrite the return address on the stack.
Step 2: Payload Delivery: The attacker, with local access to the system, submits the crafted payload to the vulnerable nvdla_emu_task_submit function, likely through a device driver interface.
Step 3: Buffer Overflow: The nvdla_emu_task_submit function processes the input without proper validation. The crafted payload overwrites the stack-allocated buffer, overflowing into adjacent memory regions.
Step 4: Control Hijack: The overflow overwrites the return address on the stack. When the nvdla_emu_task_submit function returns, control is transferred to an address controlled by the attacker.
Step 5: Code Execution: The attacker's controlled address points to malicious code, such as a shellcode, that executes with kernel privileges. This shellcode can then be used to escalate privileges, compromise the system, or cause a denial-of-service.
The vulnerability lies within the nvdla_emu_task_submit function in NVIDIA's Linux GPU drivers. This function is responsible for handling task submissions to the NVIDIA Deep Learning Accelerator (NVDLA) emulator. The root cause is a stack-based buffer overflow due to insufficient bounds checking on user-supplied input data. Specifically, the function fails to validate the size or content of data passed to it, allowing an attacker to write beyond the allocated buffer on the stack. This can overwrite adjacent stack frames, including the return address, enabling the attacker to redirect execution flow to arbitrary code, leading to privilege escalation. The lack of input validation allows for a crafted input that overflows a buffer, overwriting critical data on the stack. This could include function pointers, return addresses, or other sensitive data, enabling arbitrary code execution within the kernel context. The vulnerability does not appear to be caused by a race condition.
While no specific APT groups are directly linked to this CVE, the nature of the vulnerability makes it attractive to various threat actors. Given the potential for privilege escalation, it is likely that this vulnerability is being targeted by groups seeking to maintain persistence or gain access to sensitive data. CISA KEV status is not available in the provided information.
Monitor system logs for unusual activity related to NVIDIA GPU drivers, including errors or crashes related to the nvdla_emu_task_submit function.
Analyze kernel crash dumps for evidence of stack corruption or memory overflows.
Implement file integrity monitoring to detect changes to NVIDIA driver files.
Monitor network traffic for any unusual communication patterns originating from the compromised system.
Use intrusion detection systems (IDS) and intrusion prevention systems (IPS) with signatures designed to detect exploitation attempts against NVIDIA drivers. These signatures should look for specific patterns in the input data that trigger the buffer overflow.
Examine system calls related to NVIDIA drivers for suspicious parameters or sequences.
Update NVIDIA GPU drivers to a patched version that addresses CVE-2022-42270. This is the primary and most effective remediation step.
Implement a defense-in-depth strategy, including least privilege access control, to limit the impact of a successful exploit.
Regularly scan systems for vulnerabilities using vulnerability scanners.
Enable kernel address space layout randomization (KASLR) to make exploitation more difficult.
Harden the system by disabling unnecessary services and features.
Monitor system logs and security events for suspicious activity.