Bug 2528679 (CVE-2026-80832)

Summary: CVE-2026-80832 kernel: crypto: qce - fix CCM AAD buffer underallocation
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Doc Text:
A flaw was found in the Linux kernel's QCE (Qualcomm Crypto Engine) cryptographic module. An issue with buffer underallocation in the `qce_aead_ccm_prepare_buf_assoclen()` function can lead to the allocated AAD (Additional Authenticated Data) buffer being smaller than required for DMA (Direct Memory Access) operations. This allows the QCE hardware to read beyond the buffer's boundaries when computing the CBC-MAC (Cipher Block Chaining Message Authentication Code) for associated data. As a result, extra data is incorporated into the authentication tag, which can lead to an incorrect tag and impact the integrity and authentication of cryptographic operations.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-09-04 16:23:54 UTC 
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.
Comment 1 gkamathe 2026-09-07 12:47:12 UTC 
Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-80832.mbox