blktrace: Use-After-Free Vulnerability in blk_trace Access
Summary
GSD-2021-1001517: blktrace: Fix uaf in blk_trace access after removing by sysfs. Affects Kernel versions >= c71a896154119f4ca9e89d6078f5f63ad60ef199, < dacfd5e4d1142bfb3809aab3634a375f6f373269. No fix is published. How to fix ↓
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Background
The package under scrutiny is Kernel, which is a component of the Linux ecosystem. The Kernel is responsible for managing the core functionalities of the operating system, including hardware interactions, process management, and memory allocation. It serves as the bridge between the hardware and software layers, enabling applications to communicate with the underlying system resources. The vulnerability affects the blktrace module within the Kernel, which is used for block layer tracing. Block layer tracing allows users to monitor and analyze I/O operations at the block layer, providing insights into disk I/O patterns and performance. However, a use-after-free vulnerability has been identified in the blk_trace access after removing by sysfs.
Vulnerability Detail
The use-after-free vulnerability in blk_trace access occurs when the blktrace module attempts to access a block trace that has been removed by sysfs. This can lead to a situation where the module accesses freed memory, potentially resulting in a crash or the execution of arbitrary code. An attacker with local access to the system could exploit this vulnerability to escalate privileges, gain unauthorized access to sensitive information, or disrupt the normal operation of the system. The vulnerability was introduced in version v2.6.30 of the Linux Kernel and has been fixed in version v4.9.285.
How To Fix
No fixed version is published for this vulnerability.
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Workaround
As a workaround, users can disable the blktrace module if it is not required for their specific use case. This can be done by blacklisting the module or removing it from the system entirely. However, it is important to note that this workaround may impact the ability to perform block layer tracing and gather related insights.
Conclusion
In conclusion, the blktrace module in the Kernel is affected by a use-after-free vulnerability in blk_trace access. This vulnerability can be mitigated by updating the Linux Kernel to version v4.9.285 or later. Alternatively, users can disable the blktrace module if it is not required for their specific use case. It is important to stay vigilant and keep systems up to date to protect against potential exploits. For further support on vulnerability remediation, please contact DevNack.com.
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FAQ
The vulnerability could allow an attacker with local access to the system to escalate privileges, gain unauthorized access to sensitive information, or disrupt the normal operation of the system.
You can use Vulert's playground (https://vulert.com/scanner) to check if your system is affected by this vulnerability. Simply upload your manifest file (e.g., package-lock.json) to the playground, and Vulert will analyze it in real-time to identify any open-source vulnerabilities, including this one.
Yes, a patch for this vulnerability is available in version v4.9.285 of the Linux Kernel. It is recommended to update to this version or a later one to mitigate the vulnerability.
Yes, as a workaround, you can disable the blktrace module if it is not required for your specific use case. This can be done by blacklisting the module or removing it from the system entirely. However, keep in mind that this may impact the ability to perform block layer tracing.
For more information about this vulnerability, you can refer to the source link provided in the database_specific section of the vulnerability details (https://github.com/cloudsecurityalliance/gsd-database/blob/main/2021/1001xxx/GSD-2021-1001517.json). Additionally, you can reach out to info@devnack.com for further support on vulnerability remediation.
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