mtd: Require Write Permissions for Locking and Badblock IOCTLs
Summary
GSD-2021-1000388: mtd: require write permissions for locking and badblock ioctls. Affects Kernel versions >= f7e6b19bc76471ba03725fe58e0c218a3d6266c3, < 7b6552719c0ccbbea29dde4be141da54fdb5877e. No fix is published. How to fix ↓
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Background
The Kernel package is a crucial component of the Linux operating system. It provides the core functionality and interfaces for various hardware devices and software components. The Memory Technology Device (MTD) subsystem within the Kernel is responsible for managing flash memory devices. It allows for operations such as reading, writing, erasing, and locking memory regions. However, a vulnerability has been identified in the MTD subsystem that allows unauthorized users to perform locking and badblock operations without the necessary write permissions.
Vulnerability Detail
The vulnerability in the MTD subsystem arises from a lack of proper permission checks for locking and badblock IOCTLs (Input/Output Control). This means that any user, even without write permissions, can execute these IOCTLs and potentially modify or lock memory regions on flash devices. An attacker could exploit this vulnerability to gain unauthorized access, manipulate data, or disrupt the normal functioning of the system. The vulnerability was introduced in Linux Kernel version 5.9 and has been fixed in version 5.10.37.
How To Fix
No fixed version is published for this vulnerability.
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Workaround
As a workaround, users can restrict access to the affected IOCTLs by modifying the permissions of the corresponding device files. By ensuring that only users with write permissions can execute these IOCTLs, the vulnerability can be mitigated. Below is an example of how to modify the permissions using the 'chmod' command:
$ chmod o-w /dev/mtdX
Replace 'mtdX' with the appropriate device file for the flash memory device.
Conclusion
The vulnerability in the MTD subsystem of the Linux Kernel allows unauthorized users to perform locking and badblock operations without the necessary write permissions. This can lead to unauthorized access, data manipulation, and disruption of system functionality. It is crucial to update the Kernel to version 5.10.37 or later to fix this vulnerability. Additionally, restricting access to the vulnerable IOCTLs through proper permissions can serve as a temporary workaround. For further assistance and support in vulnerability remediation, please contact DevNack.com.
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FAQ
This vulnerability allows unauthorized users to perform locking and badblock operations on flash memory devices without the necessary write permissions. It can lead to unauthorized access, data manipulation, and disruption of system functionality.
You can use the Vulert Playground (https://vulert.com/scanner) to check if your system is affected by this vulnerability. Simply upload your package-lock.json file and it will analyze the dependencies to identify any vulnerable versions of the Linux Kernel.
There is no evidence of this vulnerability being exploited in the wild at the time of discovery. However, it is important to apply the necessary updates and security measures to mitigate the risk.
Yes, a workaround is available by modifying the permissions of the affected device files to restrict access to the vulnerable IOCTLs. Please refer to the 'workaround' section for detailed instructions.
Yes, the vulnerability has been fixed in Linux Kernel version 5.10.37. It is recommended to update to this version or a later one to ensure the vulnerability is mitigated.
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