Linux Kernel up to 6.9.6 ext4 ext4_xattr_set_entry allocation of resources

Summaryinfo

A vulnerability, which was classified as problematic, was found in Linux Kernel up to 6.9.6. This issue affects the function ext4_xattr_set_entry of the component ext4. The manipulation results in allocation of resources. This vulnerability was named CVE-2024-40972. There is no available exploit. You should upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as problematic, was found in Linux Kernel up to 6.9.6. Affected is the function ext4_xattr_set_entry of the component ext4. The manipulation with an unknown input leads to a allocation of resources vulnerability. CWE is classifying the issue as CWE-770. The product allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor. The impact remains unknown. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: ext4: do not create EA inode under buffer lock ext4_xattr_set_entry() creates new EA inodes while holding buffer lock on the external xattr block. This is problematic as it nests all the allocation locking (which acquires locks on other buffers) under the buffer lock. This can even deadlock when the filesystem is corrupted and e.g. quota file is setup to contain xattr block as data block. Move the allocation of EA inode out of ext4_xattr_set_entry() into the callers.

The advisory is shared for download at git.kernel.org. This vulnerability is traded as CVE-2024-40972 since 07/12/2024. There are known technical details, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 207773 (Oracle Linux 8 : kernel (ELSA-2024-7000)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.9.7 eliminates this vulnerability. Applying the patch 111103907234/0a46ef234756 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (207773). Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.9.0
• 6.9.1
• 6.9.2
• 6.9.3
• 6.9.4
• 6.9.5
• 6.9.6

License

• open-source

Website

• Vendor: https://www.kernel.org/

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Once again VulDB remains the best source for vulnerability data.

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