ext4: Bug in Handling Dirty Pages without Permission
Summary
GSD-2022-1002219: ext4: don't BUG if someone dirty pages without asking ext4 first. Affects Kernel versions < 5a016c053f426a73752c3b41b60b497b58694d48. No fix is published. How to fix ↓
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Background
The ext4 package is a file system driver for the Linux Kernel. It provides support for the fourth extended file system (ext4), which is commonly used in Linux distributions. The ext4 file system offers improved performance, scalability, and reliability compared to its predecessors. However, a vulnerability has been discovered in the ext4 driver that allows someone to dirty pages without obtaining permission from ext4 first.
Vulnerability Detail
The vulnerability in the ext4 driver arises from a bug that allows unauthorized modification of dirty pages. Dirty pages are memory pages that have been modified but not yet written back to disk. Normally, ext4 should be responsible for handling the dirty pages and ensuring their proper synchronization with the file system. However, due to this bug, an attacker can bypass ext4's permission checks and directly modify the dirty pages. This could lead to data corruption, integrity issues, or even a system crash. 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 solution is to update the Linux Kernel to the fixed version.
Conclusion
The ext4 driver in the Linux Kernel is vulnerable to a bug that allows unauthorized modification of dirty pages. This could result in data corruption, integrity issues, or system crashes. The vulnerability has been fixed in Linux Kernel version v5.4.189. It is recommended to update the Linux Kernel to this version or a later one that includes the fix. For further support on vulnerability remediation, please contact DevNack.com.
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FAQ
ext4 is a file system driver for the Linux Kernel, providing support for the fourth extended file system (ext4). It offers improved performance, scalability, and reliability compared to previous file system versions.
A dirty page refers to a memory page that has been modified but not yet written back to disk. It contains data that needs to be synchronized with the file system.
The impact of this vulnerability could include data corruption, integrity issues, or system crashes. However, the actual impact and attack plausibility have not been proven yet.
To fix this vulnerability, update your Linux Kernel to version v5.4.189 or a later version that includes the fix.
No specific workaround has been mentioned for this vulnerability. Updating the Linux Kernel to the fixed version is the recommended solution.
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