Vulnerability in Kernel: blk-cgroup UAF
Summary
GSD-2021-1001606: blk-cgroup: fix UAF by grabbing blkcg lock before destroying blkg pd. Affects Kernel versions < d12ddd843f1877de1f7dd2aeea4907cf9ff3ac08. No fix is published. How to fix ↓
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Background
The Kernel is a crucial component of the Linux operating system, responsible for managing system resources and facilitating communication between hardware and software. It provides essential functionalities such as process management, memory management, and device drivers. The blk-cgroup subsystem within the Kernel is responsible for controlling and monitoring block devices. It allows for resource allocation and tracking of I/O operations on block devices. However, a vulnerability has been identified in the blk-cgroup subsystem that could lead to a use-after-free (UAF) condition.
Vulnerability Detail
The identified vulnerability in the blk-cgroup subsystem arises from a failure to acquire the necessary lock before destroying a block group (blkg) per-device (pd) structure. This UAF vulnerability could potentially be exploited by an attacker to execute arbitrary code or cause a denial-of-service (DoS) condition. By manipulating the timing of the destruction of the blkg pd structure, an attacker could gain control over freed memory and potentially execute malicious code. 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
There is no specific workaround mentioned for this vulnerability. The recommended approach is to apply the fix provided in the latest version of the Linux Kernel.
Conclusion
The identified vulnerability in the Kernel's blk-cgroup subsystem could potentially lead to arbitrary code execution or a denial-of-service condition. It is crucial to update to the latest version of the Linux Kernel (v5.4.150 or later) to mitigate this vulnerability. For further support and assistance in vulnerability remediation, please contact DevNack.com.
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FAQ
The impact of this vulnerability could range from arbitrary code execution to a denial-of-service condition, depending on the attacker's ability to exploit the use-after-free condition.
By manipulating the timing of the destruction of the blkg pd structure, an attacker could gain control over freed memory and potentially execute arbitrary code.
There is no evidence of this vulnerability being exploited in the wild at the time of discovery.
The vulnerability is present in versions of the Linux Kernel prior to v5.4.150. It has been fixed in this version and subsequent releases.
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