CVE-2023-53563

/// Technical description

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

cpufreq: amd-pstate-ut: Fix kernel panic when loading the driver

After loading the amd-pstate-ut driver, amd_pstate_ut_check_perf()

and amd_pstate_ut_check_freq() use cpufreq_cpu_get() to get the policy

of the CPU and mark it as busy.

In these functions, cpufreq_cpu_put() should be used to release the

policy, but it is not, so any other entity trying to access the policy

is blocked indefinitely.

One such scenario is when amd_pstate mode is changed, leading to the

following splat:

[ 1332.103727] INFO: task bash:2929 blocked for more than 120 seconds.

[ 1332.110001] Not tainted 6.5.0-rc2-amd-pstate-ut #5

[ 1332.115315] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

[ 1332.123140] task:bash state:D stack:0 pid:2929 ppid:2873 flags:0x00004006

[ 1332.123143] Call Trace:

[ 1332.123145] <TASK>

[ 1332.123148] __schedule+0x3c1/0x16a0

[ 1332.123154] ? _raw_read_lock_irqs

/// 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