Linux Kernel Memory Leak Vulnerability in mlx5 Direct Rule Command Handling

A memory leak vulnerability has been identified in the Linux kernel's handling of direct rule commands for Mellanox mlx5 devices. This issue arises in the 'mlx5dr_cmd_create_reformat_ctx' function, where the 'in' parameter's memory is not properly released if the 'mlx5_cmd_exec' command execution fails. The oversight leads to a memory leak, as the allocated memory is not freed. The vulnerability affects several versions of the Linux kernel.

Impact

Exploitation of this vulnerability leads to a memory leak, where allocated memory is not properly released, potentially causing increased memory usage and degradation of system performance over time.

Reproduction

The vulnerability can be reproduced by invoking the 'mlx5dr_cmd_create_reformat_ctx' function with parameters that cause the 'mlx5_cmd_exec' function to fail. This failure can be simulated by providing invalid or malformed input data that the command execution cannot process, such as incorrect command lengths or unsupported command types. When 'mlx5_cmd_exec' fails, the function does not release the memory pointed to by 'in', leading to a memory leak.

Remediation

Users can upgrade to the latest version of the Linux kernel where this vulnerability has been addressed. The specific commit that resolves this issue is available in the Linux kernel stable tree.