CVE-2023-53169

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

x86/resctrl: Clear staged_config[] before and after it is used

As a temporary storage, staged_config[] in rdt_domain should be cleared

before and after it is used. The stale value in staged_config[] could

cause an MSR access error.

Here is a reproducer on a system with 16 usable CLOSIDs for a 15-way L3

Cache (MBA should be disabled if the number of CLOSIDs for MB is less than

16.) :

mount -t resctrl resctrl -o cdp /sys/fs/resctrl

mkdir /sys/fs/resctrl/p{1..7}

umount /sys/fs/resctrl/

mount -t resctrl resctrl /sys/fs/resctrl

mkdir /sys/fs/resctrl/p{1..8}

An error occurs when creating resource group named p8:

unchecked MSR access error: WRMSR to 0xca0 (tried to write 0x00000000000007ff) at rIP: 0xffffffff82249142 (cat_wrmsr+0x32/0x60)

Call Trace:

<IRQ>

__flush_smp_call_function_queue+0x11d/0x170

__sysvec_call_function+0x24/0xd0

sysvec_call_function+0x89/0xc0

</IRQ>

<TASK>

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References