Linux Kernel High-Order Sequence Bit Handling Vulnerability in Out-of-Place Decryption

A vulnerability exists in the Linux kernel's handling of high-order sequence bits during out-of-place decryption in the 'authencesn' crypto module. When decrypting data that is not processed in-place, the kernel unnecessarily saves the high-order sequence bits in the destination buffer, instead of simply copying them from the source. This flaw requires the data to be rearranged before hashing, potentially leading to incorrect decryption or authentication errors.

Impact

The vulnerability could cause improper decryption of data, leading to authentication errors or incorrect processing of encrypted information.

Reproduction

The vulnerability can be reproduced by using the 'authencesn' crypto module to decrypt data that is not in-place, while the high-order sequence bits are incorrectly handled. This can be done by creating a scenario where the source and destination buffers are different, and the 'authencesn' module is used to perform decryption without the necessary adjustments for the sequence bits.

Remediation

Users can upgrade to the latest version of the Linux kernel where this vulnerability has been addressed. Instructions for upgrading the kernel can be found in the official Linux documentation.