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.
Metrics
No CVSS score has been published yet.
Affected software
Source: the vendor's advisory (CNA). NVD analysis pending.
No affected versions have been published.
Timeline
- Published
- Sep 4, 2026
- Last modified
- Oct 19, 2026
- NVD status
- Received