Linux Kernel KSMBD Component Integer Overflow Vulnerability in IPC Message Validation

A vulnerability in the Linux kernel's KSMBD component allows for integer overflow in the validation of response sizes within the IPC message handling. This issue arises because the expected message size is calculated by adding or multiplying attacker-controlled fields from the daemon response with a fixed struct size, using unsigned integer arithmetic. Three specific response types are affected: RPC requests, share configuration requests, and extended login requests. In these cases, the manipulation of response sizes can lead to a bypass of size checks, allowing downstream processes to trust unverified lengths, potentially causing memory corruption or other unintended behavior.

Impact

Exploitation of this vulnerability can lead to integer overflow, allowing for the manipulation of memory operations that trust unverified lengths, which could be exploited to cause memory corruption or other unintended behaviors in the application.

Reproduction

The vulnerability can be reproduced by sending crafted responses to the KSMBD server that include payload sizes or group counts designed to trigger the integer overflow in the IPC message validation. This can be done using tools that interact with the SMB protocol and manipulate response sizes, such as custom scripts or applications that exploit the KSMBD IPC response handling.

Remediation

Users can update to the latest version of the Linux kernel where this vulnerability has been addressed. Instructions for updating the kernel can be found in the official Linux documentation or through the package management system used by the distribution.