Linux Kernel Integer Overflow Vulnerability in iwlwifi Debugfs Monitor Data

An integer overflow vulnerability has been identified in the Linux kernel's iwlwifi driver, specifically within the debugfs monitor data handling. This issue arises in the iwl_write_to_user_buf function, which is invoked by iwl_dbgfs_monitor_data_read. The vulnerability occurs when a user supplies a SIZE_MAX value for the count parameter, leading to a negative buffer size calculation. This miscalculation allows for a heap overflow when the adjusted size is passed to the copy_to_user function. However, this vulnerability is not considered a security risk, as the affected debugfs operation is restricted to 0400 privileges.

Impact

Exploitation of this vulnerability causes a heap overflow, which can potentially lead to memory corruption.

Reproduction

To reproduce this vulnerability, invoke the iwl_dbgfs_monitor_data_read function with a SIZE_MAX value for the count parameter. This can be done by writing a user-space program or script that interacts with the debugfs interface of the iwlwifi driver, specifically targeting the monitor data read operation. The program should pass the maximum size value, which will trigger the integer overflow in the iwl_write_to_user_buf function.

Remediation

Users can update to the latest version of the Linux kernel where this vulnerability has been patched. Instructions for updating the kernel can be found in the official Linux kernel documentation.