{"id":"CVE-2026-80662","title":"In the Linux kernel, the following vulnerability has been resolved:\n\ncxl: Fix CXL_HEADERLOG_SIZE to match RAS Capability size\n\nThe CXL r4.0 8.2.4.17.7 RAS Capability Structure has total length 0x58\nbytes (CXL_RAS_CAPABILITY_LENGTH); the …","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\ncxl: Fix CXL_HEADERLOG_SIZE to match RAS Capability size\n\nThe CXL r4.0 8.2.4.17.7 RAS Capability Structure has total length 0x58\nbytes (CXL_RAS_CAPABILITY_LENGTH); the …","severity":"high","cvss":7.1,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","published":"2026-08-28","updated":"2026-08-29","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-80662","references":[{"url":"https://git.kernel.org/stable/c/6fc1919a6f2ed541484dd1f6cd93374044f8fd3d","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c268f949e219f9e179558e836f457f6c5fbec416","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/fc5eb0962a5e50d64e711817cc24d67df2d90528","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-80662.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-80662"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2525422"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-80662"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-80662"},{"url":"https://lore.kernel.org/linux-cve-announce/2026082846-CVE-2026-80662-9cad@gregkh/T"},{"url":"https://git.kernel.org/stable/c/d031617045dc743764ea574432e5c2a3757b4e57"},{"url":"https://git.kernel.org/stable/c/e3e8f3b760bcf6a4b3aec412015b74b578729006"}],"tags":["nvd","csaf","vex","red-hat","cve.org"],"epss":0.00166,"epssPercentile":0.05769,"ingestedAt":"2026-08-30T03:46:31.469Z","vendor":"Red Hat","cwe":["CWE-125"],"scores":{"nvd":7.1,"vendor":5.5,"cna":7.1},"product":"Linux","affected":["Linux >= 2905cb5236cba63a5dc8a83752dcc31f3cc819f9 < d031617045dc743764ea574432e5c2a3757b4e57","Linux >= 2905cb5236cba63a5dc8a83752dcc31f3cc819f9 < e3e8f3b760bcf6a4b3aec412015b74b578729006","Linux >= 2905cb5236cba63a5dc8a83752dcc31f3cc819f9 < 6fc1919a6f2ed541484dd1f6cd93374044f8fd3d","Linux >= 2905cb5236cba63a5dc8a83752dcc31f3cc819f9 < fc5eb0962a5e50d64e711817cc24d67df2d90528","Linux >= 2905cb5236cba63a5dc8a83752dcc31f3cc819f9 < c268f949e219f9e179558e836f457f6c5fbec416","Linux 6.2"],"slug":"CVE-2026-80662","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\ncxl: Fix CXL_HEADERLOG_SIZE to match RAS Capability size\n\nThe CXL r4.0 8.2.4.17.7 RAS Capability Structure has total length 0x58\nbytes (CXL_RAS_CAPABILITY_LENGTH); the Header Log occupies the trailing\n64 bytes at offset 0x18.  CXL_HEADERLOG_SIZE was defined as SZ_512,\neight times the actual on-device size.\n\nheader_log_copy() reads CXL_HEADERLOG_SIZE_U32 (128) dwords from the\nRAS capability iomap, overrunning the 88-byte mapping by 448 bytes.\nThe cxl_aer_uncorrectable_error trace event memcpy()s CXL_HEADERLOG_SIZE\n(512) bytes from its source.  For the CPER caller the source is\nstruct cxl_ras_capability_regs::header_log[16] (64 bytes) embedded in a\nstack-local cxl_cper_prot_err_work_data, so the memcpy reads 448 bytes\nof kernel stack into the trace event ring buffer where userspace can\nread it via tracefs.\n\nSet CXL_HEADERLOG_SIZE to 64 and derive CXL_HEADERLOG_SIZE_U32 from it,\nbringing all iomap readers into agreement on 16 dwords.  Userspace tools\nsuch as rasdaemon have grown a dependency on the buggy 512-byte (128 u32)\nheader_log layout in the cxl_aer_uncorrectable_error trace event.  Add\nCXL_HEADERLOG_TRACE_SIZE_U32 = 128 and use it for the trace event\n__array and its memcpy to preserve that ABI.  Both callers now pass a\nzero-filled u32[CXL_HEADERLOG_TRACE_SIZE_U32] staging buffer with only\nthe first CXL_HEADERLOG_SIZE_U32 (16) entries populated from hardware;\nthe remaining 112 u32s are zero-padded, keeping the 512-byte trace ring\nbuffer layout intact.\n\n[ dj: Replaced 64 with SZ_64 per RichardC ]\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · updated 2026-10-17 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-80662.json)","depth":"twilight","depthScore":39,"depthScoreParts":{"impact":39.1,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}