ext4: Fix Use-After-Free in ext4_rename_dir_prepare
Summary
GSD-2022-1003844: ext4: fix use-after-free in ext4_rename_dir_prepare. Affects Kernel versions < 10801095224de0d0ab06ae60698680c1f883a3ae. No fix is published. How to fix ↓
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Background
The ext4 filesystem is a widely used file system in the Linux kernel. It provides features such as journaling, support for large file systems, and improved performance. The ext4_rename_dir_prepare function is responsible for preparing a directory for renaming in the ext4 file system. However, a use-after-free vulnerability has been discovered in this function, which could be exploited by an attacker to execute arbitrary code or cause a denial-of-service attack.
Vulnerability Detail
The use-after-free vulnerability in ext4_rename_dir_prepare occurs when the function fails to properly handle a directory entry that is being renamed. This can lead to a situation where a reference to the directory entry is freed, but still accessible by an attacker. By manipulating the freed memory, an attacker could execute arbitrary code or crash the system. The impact of this vulnerability depends on the attacker's ability to control the freed memory and the privileges of the affected process.
How To Fix
No fixed version is published for this vulnerability.
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Workaround
There is no known workaround for this vulnerability. It is recommended to apply the fix provided by the Linux kernel developers.
Conclusion
The use-after-free vulnerability in ext4_rename_dir_prepare can be fixed by updating the Linux kernel to version v4.19.247 or later. It is important to apply this fix to ensure the security and stability of the system. For further support on vulnerability remediation, please contact DevNack.com.
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FAQ
ext4 is a file system used in the Linux kernel. It provides features such as journaling, support for large file systems, and improved performance.
A use-after-free vulnerability occurs when a program continues to use a memory reference after it has been freed. This can lead to memory corruption and potentially allow an attacker to execute arbitrary code or crash the system.
ext4_rename_dir_prepare is a function in the ext4 file system that prepares a directory for renaming. It is responsible for handling the necessary operations to rename a directory entry.
The impact of this vulnerability depends on the attacker's ability to control the freed memory and the privileges of the affected process. It could potentially allow an attacker to execute arbitrary code or crash the system.
To fix this vulnerability, it is recommended to update the Linux kernel to version v4.19.247 or later. This fix is included in commit 10801095224de0d0ab06ae60698680c1f883a3ae of the Linux kernel source code.
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