Affected: Alpaquita:23: linux-lts, Alpaquita:25: linux-lts, Alpaquita:stream: linux-lts

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.

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.

kernel-devel-7.2.5-1.1 on GA media

Affected: Ubuntu:16.04:LTS: linux-hwe-edge, Ubuntu:18.04:LTS: linux-aws-5.0, Ubuntu:18.04:LTS: linux-aws-5.3, Ubuntu:18.04:LTS: linux-azure, Ubuntu:18.04:LTS: linux-azure-5.3, Ubuntu:18.04:LTS: linux-azure-edge, Ubuntu:18.04:LTS: linux-gcp, Ubuntu:18.04:LTS: linux-gcp-5.3, Ubuntu:18.04:LTS: linux-gke-4.15, Ubuntu:18.04:LTS: linux-gke-5.4 and 193 more

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.

Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in Linux Kernel ausnutzen, um Speicherfehler und Kernel-Abstürze beziehungsweise Denial-of-Service-Zustände auszulösen, Speicher außerhalb vorgesehener Grenzen auszulesen sowie in einzelnen Fällen weitere Sicherheitsauswirkungen zu verursachen.