CVE-2020-14356

What it actually does

Null pointer dereference in the cgroupv2 subsystem on system reboot allows a local process to trigger a kernel crash or privilege escalation.

Why it matters to the business

Local users can crash production systems or obtain higher privileges, leading to downtime and potential unauthorized access; the issue has been public for over six years with exploits available.

How an attack unfolds

An attacker with local shell access on an unpatched system initiates a reboot, causing the kernel cgroupv2 code path to dereference a null pointer and either panic the system or allow privilege escalation.

How to fix it

Update the Linux kernel to version 5.7.10 or later; for affected TensorFlow GIT installations apply commit 1e922ccdf6bf46a3a52641f99fd47d54c1decd13.

How to confirm the fix worked

Confirm kernel version is at least 5.7.10 and verify TensorFlow GIT revision matches the listed fixed commit.

Typical attack path

1. Gain local user access to the target system
2. Trigger a system reboot while cgroupv2 is active
3. Kernel dereferences null pointer during reboot handling
4. Resulting crash or successful privilege escalation

How to detect it

Review system logs for kernel oops or panic messages around reboot events and check process activity preceding reboots for unusual local user behavior.

What your security team should do

• Prioritize kernel upgrades on all systems running versions before 5.7.10
• Audit local user accounts and limit reboot privileges where possible
• Monitor for available public exploits and test patches in staging environments