CVE-2022-50769 in Linux
Summary
by MITRE • 12/24/2025
In the Linux kernel, the following vulnerability has been resolved:
mmc: mxcmmc: fix return value check of mmc_add_host()
mmc_add_host() may return error, if we ignore its return value, the memory that allocated in mmc_alloc_host() will be leaked and it will lead a kernel crash because of deleting not added device in the remove path.
So fix this by checking the return value and goto error path which will call mmc_free_host().
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Analysis
by VulDB Data Team • 04/21/2026
The vulnerability identified as CVE-2022-50769 represents a critical memory management flaw within the Linux kernel's multimedia card host controller driver, specifically affecting the mxcmmc driver used in i.MX platform systems. This issue stems from improper error handling in the device initialization sequence where the mmc_add_host() function's return value is not properly validated. The mxcmmc driver is responsible for managing multimedia card communications on Freescale i.MX SoC platforms, making this vulnerability particularly significant for embedded systems and industrial computing devices that rely on these processors. The flaw exists in the kernel's device management subsystem where memory allocation and deallocation operations are not properly synchronized with error conditions.
The technical implementation of this vulnerability occurs when the mmc_alloc_host() function successfully allocates memory for a multimedia card host structure but the subsequent mmc_add_host() call fails due to various conditions such as resource exhaustion, device conflicts, or hardware initialization errors. When the return value from mmc_add_host() is ignored, the allocated memory remains unreleased and becomes orphaned within the kernel's memory management system. This memory leak creates a cascade of issues where the kernel attempts to remove a device that was never properly registered, leading to kernel panic conditions and system crashes. The vulnerability directly violates proper resource management practices and demonstrates a classic case of improper error handling in kernel space code.
The operational impact of this vulnerability extends beyond simple system instability to potentially compromise the reliability of embedded systems that depend on multimedia card functionality for critical operations. Devices using i.MX processors in industrial automation, automotive systems, or embedded computing applications may experience unexpected system failures when multimedia card operations are attempted. The vulnerability can be exploited through normal device initialization sequences, making it particularly dangerous as it does not require special privileges or complex attack vectors. Security implications include potential denial of service conditions that could affect system availability, especially in mission-critical environments where continuous operation is essential. The flaw affects kernel versions that include the mxcmmc driver implementation and requires immediate patching to prevent exploitation.
Mitigation strategies for CVE-2022-50769 focus on implementing proper error handling mechanisms within the kernel's device management code. The fix involves adding explicit return value checks for mmc_add_host() calls and implementing proper error paths that ensure mmc_free_host() is invoked when initialization fails. This approach aligns with established security practices outlined in the Common Weakness Enumeration (CWE) category CWE-459, which addresses incomplete cleanup and improper error handling. The solution follows the principle of least privilege and proper resource management as recommended by the ATT&CK framework's system hardening tactics. System administrators should prioritize applying kernel updates that include this patch, particularly in environments where device stability and availability are paramount. Additionally, monitoring for kernel panic events and system crashes related to multimedia card operations can help identify systems that may not have received the necessary security updates.