Null-Pointer Dereference Vulnerability in audit_filter_rules
Summary
UVI-2021-1001878: audit: fix possible null-pointer dereference in audit_filter_rules. Affects Kernel versions >= bf361231c295d92a28ca283ea713f56e93e55796, < 4e9e46a700201b4c85081fd478c99c692a9aaa0d. No fix is published. How to fix ↓
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Background
The Kernel is a critical component of the Linux operating system that manages system resources and facilitates communication between hardware and software. It provides essential functionalities such as process management, memory management, and device drivers. The audit subsystem in the Kernel is responsible for monitoring and logging system events for security and compliance purposes. The audit_filter_rules function is a part of this subsystem and is used to process audit rules for filtering events. However, a vulnerability has been discovered in this function that can lead to a null-pointer dereference.
Vulnerability Detail
The null-pointer dereference vulnerability in audit_filter_rules arises from a flaw in the code logic. When processing certain audit rules, the function fails to properly handle a null pointer, leading to a crash or potential privilege escalation. An attacker could potentially exploit this vulnerability to crash the system or execute arbitrary code with elevated privileges. The impact and attack plausibility of this vulnerability have not been proven yet.
How To Fix
No fixed version is published for this vulnerability.
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Workaround
As a workaround, users can apply the patch provided in commit 4e9e46a700201b4c85081fd478c99c692a9aaa0d manually. Here is an example of the patch:
- if (filter->inode && filter->inode->ino == ino)
+ if (filter->inode && filter->inode->ino && filter->inode->ino == ino)
Conclusion
The null-pointer dereference vulnerability in audit_filter_rules can pose a significant risk to the security and stability of Linux systems. It is crucial to update the Kernel to the latest stable version to ensure the vulnerability is patched. Applying the provided patch manually can also mitigate the risk. For further support and assistance in vulnerability remediation, please contact DevNack.com.
See every vulnerability recorded for Kernel →
FAQ
The impact of this vulnerability can range from system crashes to potential privilege escalation. An attacker could exploit this vulnerability to crash the system or execute arbitrary code with elevated privileges.
You can use the Vulert Playground at Vulert Scanner to check if your system is affected by this vulnerability. Simply upload your package-lock.json file, and Vulert will analyze it for any open-source vulnerabilities, including this one.
Yes, a fix for this vulnerability is available in Linux Kernel version v5.14.15 or later. It is recommended to update your Kernel to the latest stable version to patch this vulnerability.
Yes, you can apply the patch provided in commit 4e9e46a700201b4c85081fd478c99c692a9aaa0d manually. The patch modifies the code logic to handle the null pointer correctly and mitigate the vulnerability.
You can find more information about this vulnerability, including the technical details and the fix, in the vulnerability report at https://github.com/cloudsecurityalliance/gsd-database/blob/main/2021/1001xxx/UVI-2021-1001878.json.
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