Use-After-Free Vulnerability in Linux Kernel - CVE-2022-49236
Summary
CVE-2022-49236: In the Linux kernel, the following vulnerability has been resolved: bpf: Fix UAF due to race between btf_try_get_module and load_module While working on code to populate kfunc BTF ID sets for module BTF from its initcall... Affects linux versions < 5.17.3-1. Fixed in 5.17.3-1. How to fix ↓
Check if this vulnerability affects your application
Upload a manifest or SBOM and we'll show whether you're affected, plus every other risky package in the same scan.
No signup required · Results in about 60 seconds
Habilume
Habit tracker with a companion that grows with you
Complete habits, earn Lume Points, and watch your Lume grow as you stay consistent.
Background
The Linux kernel is a core component of many operating systems, providing essential services for hardware management, process control, and system security. It supports a wide range of functionalities, including device drivers, file systems, and network protocols. The kernel's modular architecture allows for dynamic loading and unloading of modules, which can enhance system performance and flexibility. However, this modularity can also introduce vulnerabilities, such as the use-after-free issue identified in CVE-2022-49236, which arises during the initialization of modules.
Vulnerability Detail
CVE-2022-49236 is a use-after-free vulnerability in the Linux kernel that occurs due to a race condition between the BPF verifier and the module loading process. Specifically, when a module is being initialized, its BTF (BPF Type Format) can be accessed by userspace before the module is fully initialized. This leads to a scenario where the BPF program can successfully load and reference the module, but if the module initialization fails, it may be freed while still being referenced, resulting in a use-after-free condition. This vulnerability can potentially allow an attacker to execute arbitrary code or cause system instability.
How To Fix
Minimum fixed version
5.17.3-1
This is the first release that contains the fix.
sudo apt-get install --only-upgrade linuxTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
Currently, there are no specific workarounds mentioned for this vulnerability. It is recommended to apply the patch as soon as it is available to mitigate the risk.
Conclusion
CVE-2022-49236 is a significant vulnerability in the Linux kernel that arises from a race condition during module initialization, leading to a use-after-free scenario. It is essential for users to update their systems to the patched version to protect against potential exploitation. Utilizing tools like Vulert can help monitor for such vulnerabilities in real-time.
See every vulnerability recorded for linux →
FAQ
CVE-2022-49236 is a use-after-free vulnerability in the Linux kernel that can occur during the module loading process, potentially leading to arbitrary code execution.
You can check if your application is affected by using Vulert, which monitors and alerts for open-source vulnerabilities in real-time. Visit Vulert Scanner to analyze your manifest file.
The risks include potential arbitrary code execution and system instability, which can compromise the security and reliability of the affected systems.
Yes, a patch is available in version 5.17.3-1 and later of the Linux package. It is recommended to update your system to this version.
While there are no specific workarounds, it is crucial to prioritize applying the patch as soon as possible to mitigate the risks associated with this vulnerability.
Related vulnerabilities
Recent vulnerabilities recorded for linux.
Habilume
Habit tracker with a companion that grows with you
Complete habits, earn Lume Points, and watch your Lume grow as you stay consistent.
