Linux Kernel MMC ToshSD Driver Return Value Check Vulnerability

A vulnerability exists in the Linux kernel's MMC ToshSD driver, specifically in the handling of the 'mmc_add_host()' function. The driver fails to properly check the return value of this function, which can lead to a memory leak from the 'mmc_alloc_host()' allocation. This oversight can cause a kernel crash when the driver attempts to remove a device that was not successfully added. The issue has been addressed by implementing a proper return value check and adding error handling to free the allocated resources and interrupt.

Impact

The vulnerability can cause a kernel crash due to improper management of device additions and removals, leading to instability in the system.

Reproduction

The vulnerability can be reproduced by loading the Toshiba PCI SD controller driver in the Linux kernel. The driver will fail to check for errors when adding the host, allowing for a memory leak. When the driver is unloaded, it will attempt to remove a device that was never properly added, causing a crash.

Remediation

Users can upgrade to the patched version of the Linux kernel where this vulnerability has been addressed. The specific commit containing the fix is 'f670744a316ea983113a65313dcd387b5a992444', which is available in the Linux kernel stable tree.