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VulnerabilityPublished Updated

CVE-2026-80662: Linux kernel · cxl: Fix CXL_HEADERLOG_SIZE to match RAS Capability size

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 7.1 High · fixed in fc5eb0962a5e50d64e711817cc24d67df2d90528 : patch Linux kernel soon.

Data as of 26 Oct 2026, 13:47 UTC

CVSS 3.1 base score
7.1High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in fc5eb0962a5e50d64e711817cc24d67df2d90528, e3e8f3b760bcf6a4b3aec412015b74b578729006, d031617045dc743764ea574432e5c2a3757b4e57 +2
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 28 Aug 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ 2905cb5236cba63a5dc8a83752dcc31f3cc819f9, < fc5eb0962a5e50d64e711817cc24d67df2d90528
Fixed in
  • fc5eb0962a5e50d64e711817cc24d67df2d90528
LinuxLinuxAffected
  • ≥ 2905cb5236cba63a5dc8a83752dcc31f3cc819f9, < e3e8f3b760bcf6a4b3aec412015b74b578729006
Fixed in
  • e3e8f3b760bcf6a4b3aec412015b74b578729006
LinuxLinuxAffected
  • ≥ 2905cb5236cba63a5dc8a83752dcc31f3cc819f9, < d031617045dc743764ea574432e5c2a3757b4e57
Fixed in
  • d031617045dc743764ea574432e5c2a3757b4e57
LinuxLinuxAffected
  • ≥ 2905cb5236cba63a5dc8a83752dcc31f3cc819f9, < c268f949e219f9e179558e836f457f6c5fbec416
Fixed in
  • c268f949e219f9e179558e836f457f6c5fbec416
LinuxLinuxAffected
  • ≥ 2905cb5236cba63a5dc8a83752dcc31f3cc819f9, < 6fc1919a6f2ed541484dd1f6cd93374044f8fd3d
Fixed in
  • 6fc1919a6f2ed541484dd1f6cd93374044f8fd3d
LinuxLinuxAffected
  • =6.2
Fixed in–

Description

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 ]

References

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