Linux Kernel up to 6.18.41/7.1.4 CXL RAS header_log_copy out-of-bounds

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2.2$0-$5k0.00+

Summaryinfo

A vulnerability classified as problematic was found in Linux Kernel up to 6.18.41/7.1.4. Affected by this issue is the function header_log_copy of the component CXL RAS. The manipulation results in out-of-bounds. This vulnerability is identified as CVE-2026-80662. The attack is only possible with local access. There is not any exploit available.

Detailsinfo

A vulnerability, which was classified as problematic, was found in Linux Kernel up to 6.18.41/7.1.4. Affected is the function header_log_copy of the component CXL RAS. The manipulation with an unknown input leads to a out-of-bounds vulnerability. CWE is classifying the issue as CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. This is going to have an impact on confidentiality. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: cxl: Fix CXL_HEADERLOG_SIZE to match RAS Capability size The CXL r4.0 8.2.4.17.7 RAS Capability Structure has total length 0x58 bytes (CXL_RAS_CAPABILITY_LENGTH); the Header Log occupies the trailing 64 bytes at offset 0x18. CXL_HEADERLOG_SIZE was defined as SZ_512, eight times the actual on-device size. header_log_copy() reads CXL_HEADERLOG_SIZE_U32 (128) dwords from the RAS capability iomap, overrunning the 88-byte mapping by 448 bytes. The cxl_aer_uncorrectable_error trace event memcpy()s CXL_HEADERLOG_SIZE (512) bytes from its source. For the CPER caller the source is struct cxl_ras_capability_regs::header_log[16] (64 bytes) embedded in a stack-local cxl_cper_prot_err_work_data, so the memcpy reads 448 bytes of kernel stack into the trace event ring buffer where userspace can read it via tracefs. Set CXL_HEADERLOG_SIZE to 64 and derive CXL_HEADERLOG_SIZE_U32 from it, bringing all iomap readers into agreement on 16 dwords. Userspace tools such as rasdaemon have grown a dependency on the buggy 512-byte (128 u32) header_log layout in the cxl_aer_uncorrectable_error trace event. Add CXL_HEADERLOG_TRACE_SIZE_U32 = 128 and use it for the trace event __array and its memcpy to preserve that ABI. Both callers now pass a zero-filled u32[CXL_HEADERLOG_TRACE_SIZE_U32] staging buffer with only the first CXL_HEADERLOG_SIZE_U32 (16) entries populated from hardware; the remaining 112 u32s are zero-padded, keeping the 512-byte trace ring buffer layout intact. [ dj: Replaced 64 with SZ_64 per RichardC ]

The advisory is available at git.kernel.org. This vulnerability is traded as CVE-2026-80662 since 08/26/2026. The exploitability is told to be easy. Local access is required to approach this attack. The exploitation needs additional levels of successful authentication. Technical details are known, but there is no available exploit.

Upgrading to version 6.18.42 or 7.1.5 eliminates this vulnerability. Applying the patch 6fc1919a6f2ed541484dd1f6cd93374044f8fd3d/fc5eb0962a5e50d64e711817cc24d67df2d90528/c268f949e219f9e179558e836f457f6c5fbec416 is able to eliminate this problem.

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Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 2.3
VulDB Meta Temp Score: 2.2

VulDB Base Score: 2.3
VulDB Temp Score: 2.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Out-of-bounds
CWE: CWE-125 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.18.42/7.1.5
Patch: 6fc1919a6f2ed541484dd1f6cd93374044f8fd3d/fc5eb0962a5e50d64e711817cc24d67df2d90528/c268f949e219f9e179558e836f457f6c5fbec416

Timelineinfo

08/26/2026 CVE reserved
08/28/2026 +2 days Advisory disclosed
08/28/2026 +0 days VulDB entry created
08/28/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-80662 (🔒)
GCVE (CVE): GCVE-0-2026-80662
GCVE (VulDB): GCVE-100-396606

Entryinfo

Created: 08/28/2026 10:46
Changes: 08/28/2026 10:46 (59)
Complete: 🔍
Cache ID: 216::103

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