CVE-2022-3115 in Linux
Summary
by MITRE • 12/15/2022
An issue was discovered in the Linux kernel through 5.16-rc6. malidp_crtc_reset in drivers/gpu/drm/arm/malidp_crtc.c lacks check of the return value of kzalloc() and will cause the null pointer dereference.
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Analysis
by VulDB Data Team • 01/12/2023
The vulnerability identified as CVE-2022-3115 represents a critical null pointer dereference flaw within the Linux kernel version 5.16-rc6 and earlier. This issue resides in the malidp_crtc_reset function located in the drivers/gpu/drm/arm/malidp_crtc.c file, which is part of the ARM Mali display driver subsystem. The flaw occurs when the function fails to properly validate the return value from the kzalloc() memory allocation routine, creating a scenario where subsequent operations attempt to dereference a null pointer. This type of vulnerability falls under the category of improper error handling and memory management issues that can lead to system instability and potential security implications.
The technical root cause of this vulnerability stems from the absence of proper error checking after memory allocation within the graphics driver code. When kzalloc() is called to allocate memory for the display control unit, if the allocation fails for any reason such as insufficient memory or system constraints, it returns a null pointer. However, the malidp_crtc_reset function does not verify this return value before proceeding with operations that assume the memory allocation was successful. This oversight creates a path where a null pointer dereference can occur, leading to a kernel panic or system crash when the driver attempts to access memory at address zero. Such behavior violates fundamental principles of defensive programming and can be exploited to cause denial of service conditions.
The operational impact of CVE-2022-3115 extends beyond simple system crashes, as it represents a potential entry point for more sophisticated attacks. When a null pointer dereference occurs in kernel space, it can result in complete system instability and require manual reboot to restore normal operations. This vulnerability affects systems running Linux kernels up to version 5.16-rc6 that utilize ARM Mali graphics hardware, including various embedded devices, mobile platforms, and server systems with ARM-based processors. From an attack perspective, this flaw aligns with the ATT&CK technique of privilege escalation and system compromise, as it allows for potential exploitation of kernel memory management flaws to gain unauthorized system access or cause persistent denial of service conditions.
The vulnerability demonstrates clear adherence to CWE-476, which describes "NULL Pointer Dereference" as a common weakness in software development practices. This weakness occurs when a program attempts to access memory through a pointer that has been assigned a null value, typically due to insufficient error checking after memory allocation or function calls. The flaw represents a failure in input validation and error handling protocols that should be enforced at all levels of kernel development. System administrators and security professionals should prioritize patching affected systems, as the vulnerability exists in widely used kernel versions and affects devices ranging from mobile phones to enterprise servers utilizing ARM Mali graphics processors. The recommended mitigation strategy involves updating to kernel versions that contain the fix for this memory management error, which typically includes proper validation of kzalloc() return values before proceeding with memory operations.