CVE-2019-19769

What it actually does

Use-after-free read vulnerability in perf_trace_lock_acquire allows a local attacker to access memory after it has been freed during lock tracing operations in the kernel.

Why it matters to the business

Attackers with administrative access on affected Linux systems can potentially read sensitive kernel memory or escalate privileges to fully compromise the host, risking data exposure and system takeover on unpatched servers and endpoints.

How an attack unfolds

An attacker with local high-privilege access triggers lock acquire events under perf tracing to force the kernel to read from already-freed memory structures, enabling information leaks or further memory manipulation to achieve code execution.

How to fix it

Upgrade the Linux kernel to a version later than 5.3.10 that resolves the use-after-free in perf_trace_lock_acquire; apply all vendor security updates for Fedora and other distributions shipping this kernel series.

How to confirm the fix worked

Verify running kernel version exceeds 5.3.10 and confirm absence of the vulnerable perf_trace_lock_acquire code path via source review or vendor patch notes; test that perf lock tracing no longer triggers memory faults.

Typical attack path

1. Obtain local shell with root privileges on target system
2. Enable or trigger perf lock tracing events
3. Craft workload that causes lock acquire paths to hit the vulnerable perf_trace function
4. Read or corrupt freed memory to leak data or escalate privileges

How to detect it

Review kernel logs for oops or panic messages referencing perf_trace_lock_acquire or lock events; inspect audit logs for unexpected perf tracing activation by privileged processes.

What your security team should do

• Immediately update all affected Linux kernels to patched releases
• Restrict perf tracing access to trusted users only via capabilities and namespaces
• Monitor for kernel oops or memory-related panics on systems running vulnerable versions
• Audit local privilege boundaries to reduce attack surface for high-privilege local exploits