CVE-2022-49892
📋 TL;DR
A use-after-free vulnerability in the Linux kernel's ftrace subsystem allows an attacker to cause memory corruption when multiple dynamic ftrace_ops with identical content are registered and unregistered. This affects Linux systems with ftrace enabled, potentially leading to kernel crashes or privilege escalation.
💻 Affected Systems
- Linux kernel
📦 What is this software?
Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →⚠️ Risk & Real-World Impact
Worst Case
Kernel panic, system crash, or privilege escalation to root via memory corruption leading to arbitrary code execution in kernel context.
Likely Case
Kernel crash or system instability when specific ftrace operations are performed, particularly in environments using perf or other tracing tools.
If Mitigated
Minimal impact if ftrace is disabled or systems are patched; otherwise potential for denial of service.
🎯 Exploit Status
Exploitation requires specific conditions with ftrace operations; no public exploits known as of analysis.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Fixed in kernel commits: 0e792b89e6800cd9cb4757a76a96f7ef3e8b6294, 88561a66777e7a2fe06638c6dcb22a9fae0b6733, cc1b9961a0ceb70f6ca4e2f4b8bb71c87c7a495c, ea5f2fd4640ecbb9df969bf8bb27733ae2183169
Vendor Advisory: https://git.kernel.org/stable/c/0e792b89e6800cd9cb4757a76a96f7ef3e8b6294
Restart Required: Yes
Instructions:
1. Update Linux kernel to version containing the fix commits. 2. Check your distribution's security advisories for specific patched versions. 3. Reboot the system after kernel update.
🔧 Temporary Workarounds
Disable ftrace
linuxDisable the ftrace subsystem to prevent exploitation of this vulnerability
echo 0 > /sys/kernel/debug/tracing/tracing_on
echo nop > /sys/kernel/debug/tracing/current_tracer
🧯 If You Can't Patch
- Restrict access to ftrace functionality to trusted users only
- Monitor system logs for ftrace-related errors or crashes
🔍 How to Verify
Check if Vulnerable:
Check kernel version and if ftrace is enabled: uname -r and check /sys/kernel/debug/tracing/tracing_onCheck Version:
uname -rVerify Fix Applied:
Verify kernel version includes the fix commits or is newer than vulnerable versions; check with distribution-specific tools like rpm -q kernel or dpkg -l linux-image📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages
- KASAN reports of use-after-free in ftrace
- System crashes during tracing operations
Network Indicators:
- None - this is a local vulnerability
SIEM Query:
Search for kernel logs containing 'KASAN: use-after-free' or 'ftrace' with crash indicators