{"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":"2026-09-21T13:14:55.911Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-09-21T13:14:55.911Z"},"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-rc1","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-rc1"}]}]}],"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"}}}}