CyberRota Analysis
AI-GeneratedThe vulnerability affects the Linux kernel's QCE (Quantum Cryptography Engine) implementation, specifically in the allocation of the AAD (Additional Authenticated Data) buffer, which can be underallocated compared to the DMA length. This discrepancy may lead to buffer overflows, resulting in incorrect authentication tags and potential failures in cryptographic operations. Organizations using Linux systems that rely on the QCE for encryption should prioritize addressing this issue to ensure the integrity and security of their cryptographic processes.
Original NVD Description
In the Linux kernel, the following vulnerability has been resolved: crypto: qce - fix CCM AAD buffer underallocation The AAD buffer allocated in qce_aead_ccm_prepare_buf_assoclen() can be smaller than the length later programmed into the DMA scatterlist. The allocation size is currently calculated as: ALIGN(assoclen, 16) + MAX_CCM_ADATA_HEADER_LEN while the DMA length is set to: ALIGN(assoclen + adata_header_len, 16) Since ALIGN() does not distribute over addition, the allocation can be smaller than the DMA length. For example, when assoclen = 32 and adata_header_len = 2: allocation = ALIGN(32, 16) + 6 = 38 DMA length = ALIGN(32 + 2, 16) = 48 As a result, the QCE hardware can read beyond the allocated buffer while computing the CBC-MAC over the associated data. The extra bytes are folded into the authentication tag, resulting in an incorrect tag and causing CCM self-test failures such as: alg: aead: ccm-aes-qce encryption test failed (wrong result) on test vector 8 Fix the allocation by adding the maximum possible AAD header length before alignment: ALIGN(assoclen + MAX_CCM_ADATA_HEADER_LEN, 16) This guarantees that the allocated buffer is large enough for the fully padded AAD data for all supported header sizes.