{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-89731", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.760Z", "datePublished": "2026-09-11T19:46:41.312Z", "dateUpdated": "2026-10-19T08:51:44.551Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:51:44.551Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncxl/ras: Fix cxl_rch_get_aer_info() out-of-bounds AER register read\n\ncxl_rch_get_aer_info() copies the RCH Downstream Port AER capability from\nthe RCRB MMIO block using a readl() loop bounded by sizeof(struct\naer_capability_regs). This struct is a software layout and its embedded\nstruct pcie_tlp_log is larger than the on-wire AER capability. As a\nresult the loop reads past the mapped AER register block.\n\nThe over-read also populates the software-only tail fields including\nheader_log.header_len. An out-of-range header_len passed to\npcie_print_tlp_log() can then loop past the header log buffer and cause\na second out-of-bounds read.\n\nThe read was correct when introduced, but struct pcie_tlp_log has since\ngrown (Header Log and TLP Prefix Log sizes, header_len and flit fields),\nso sizeof(struct aer_capability_regs) no longer matches the physical AER\ncapability.\n\nBound the read to the physical AER registers, header through the 16 byte\nHeader Log. Zero the destination first so the software-only fields are\ndeterministic." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H", "baseScore": 7.1, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The vulnerable cxl_rch_get_aer_info() runs only from the host PCI AER IRQ path (aer_isr → cxl_rch_handle_error → cxl_error_detected/cxl_cor_error_detected) on Restricted CXL Host/Device topologies; it is not reachable from network protocols. Local access to a CXL host is the applicable vector and is higher severity than physical card insertion.\nAC:L - Once an RCH downstream-port AER event is raised, the readl() loop copies sizeof(struct aer_capability_regs) (100 bytes) instead of the 44-byte physical Header Log with no race. Unimplemented RCRB MMIO commonly returns 0xFFFFFFFF, so header_len/flit reliably drive a second out-of-bounds read in pcie_print_tlp_log().\nPR:L - The AER ISR and CXL error handlers perform no capability check. An unprivileged local user, or a guest with a passed-through CXL endpoint, can induce CXL protocol/AER errors that reach this path; init-namespace root is not required.\nUI:N - PCIe AER interrupts are dispatched automatically by aer_isr() into the CXL PCI error handlers; no victim mount, file open, or other interactive action is required.\nS:U - The MMIO and stack out-of-bounds reads occur in the host kernel CXL/PCI AER code and do not cross a VM, IOMMU, or sandbox security boundary.\nC:H - Adjacent RCRB MMIO is copied into software-only fields including header_log.header_len; pcie_print_tlp_log() then reads log->dw[] with a u8 index up to 255 past the 14-dword array, leaking up to ~1KB of kernel stack and RCRB contents to dmesg.\nI:N - Both issues are out-of-bounds reads only: MMIO is copied into a correctly sized stack aer_capability_regs, and pcie_print_tlp_log() only reads log->dw[]. In-bounds status writel()s and length-capped scnprintf() provide no write or control-flow primitive.\nA:H - The unbounded stack read in pcie_print_tlp_log() and readl() past the physical AER capability in the RCRB can fault or raise a platform machine-check, producing a kernel oops/panic; uncorrectable CXL RAS handling can also disable CXL.mem." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/cxl/core/ras_rch.c" ], "versions": [ { "version": "6ac07883dbb5f60f7bc56a13b7a84a382aa9c1ab", "lessThan": "7f5a2a330dde8e8aa2dd80e1f3e05b6ada049607", "status": "affected", "versionType": "git" }, { "version": "6ac07883dbb5f60f7bc56a13b7a84a382aa9c1ab", "lessThan": "8bd3523df1319edc61cd391e695c84a4618516df", "status": "affected", "versionType": "git" }, { "version": "6ac07883dbb5f60f7bc56a13b7a84a382aa9c1ab", "lessThan": "8e3d9dbb25d3ddbe72b4542ec4f7c4e622fe0ced", "status": "affected", "versionType": "git" }, { "version": "6ac07883dbb5f60f7bc56a13b7a84a382aa9c1ab", "lessThan": "29458e62d0829cbc99435f3e44fd560f9bbf1da7", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/cxl/core/ras_rch.c" ], "versions": [ { "version": "6.7", "status": "affected" }, { "version": "0", "lessThan": "6.7", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.111", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.51", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.4", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "6.12.111" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "6.18.51" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "7.2.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/7f5a2a330dde8e8aa2dd80e1f3e05b6ada049607" }, { "url": "https://git.kernel.org/stable/c/8bd3523df1319edc61cd391e695c84a4618516df" }, { "url": "https://git.kernel.org/stable/c/8e3d9dbb25d3ddbe72b4542ec4f7c4e622fe0ced" }, { "url": "https://git.kernel.org/stable/c/29458e62d0829cbc99435f3e44fd560f9bbf1da7" } ], "title": "cxl/ras: Fix cxl_rch_get_aer_info() out-of-bounds AER register read", "x_generator": { "engine": "bippy-1.2.0" } } } }