{"api_version":"1","generated_at":"2026-07-23T13:57:36+00:00","cve":"CVE-2026-64034","urls":{"html":"https://cve.report/CVE-2026-64034","api":"https://cve.report/api/cve/CVE-2026-64034.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-64034","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-64034"},"summary":{"title":"net: mana: Fix TOCTOU double-fetch of hwc_msg_id from DMA buffer","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: mana: Fix TOCTOU double-fetch of hwc_msg_id from DMA buffer\n\nIn mana_hwc_rx_event_handler(), resp->response.hwc_msg_id is read from\nDMA-coherent memory and bounds-checked, then mana_hwc_handle_resp()\nre-reads the same field from the same DMA buffer for test_bit() and\npointer arithmetic.\n\nDMA-coherent memory is mapped uncacheable on x86 and is shared,\nunencrypted, in Confidential VMs (SEV-SNP/TDX), so each load goes\ndirectly to host-visible memory. A H/W can modify the value\nbetween the check and the use, bypassing the bounds validation.\n\nFix this by reading hwc_msg_id exactly once using READ_ONCE() into a\nstack-local variable in mana_hwc_rx_event_handler(), and passing the\nvalidated value as a parameter to mana_hwc_handle_resp().","state":"PUBLISHED","assigner":"Linux","published_at":"2026-07-19 16:17:43","updated_at":"2026-07-20 15:17:04"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"9.3","severity":"CRITICAL","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H","baseScore":9.3,"baseSeverity":"CRITICAL","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"CHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"9.3","severity":"CRITICAL","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H","data":{"baseScore":9.3,"baseSeverity":"CRITICAL","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/a201c66edf2ebc6cfdc3813a889ba20fecebfae3","name":"https://git.kernel.org/stable/c/a201c66edf2ebc6cfdc3813a889ba20fecebfae3","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/566f42fb67a7ebfed6650e407e5b72e6b3e83bf7","name":"https://git.kernel.org/stable/c/566f42fb67a7ebfed6650e407e5b72e6b3e83bf7","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/6180a06bbc99fd9114b8db4be6c4d46e40f046ef","name":"https://git.kernel.org/stable/c/6180a06bbc99fd9114b8db4be6c4d46e40f046ef","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/09ec063d87c2dd3fa6f3561361a017bd882e9f37","name":"https://git.kernel.org/stable/c/09ec063d87c2dd3fa6f3561361a017bd882e9f37","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/35f0f0a2536a4d604b4dbad92c85c4a8fdebb870","name":"https://git.kernel.org/stable/c/35f0f0a2536a4d604b4dbad92c85c4a8fdebb870","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/3c4db56ccd13dd020fbf43afabaee74a40ec75e4","name":"https://git.kernel.org/stable/c/3c4db56ccd13dd020fbf43afabaee74a40ec75e4","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/70ad2dff8d052a85dfef15715b531f38a29108cf","name":"https://git.kernel.org/stable/c/70ad2dff8d052a85dfef15715b531f38a29108cf","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-64034","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64034","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f a201c66edf2ebc6cfdc3813a889ba20fecebfae3 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f 70ad2dff8d052a85dfef15715b531f38a29108cf git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f 566f42fb67a7ebfed6650e407e5b72e6b3e83bf7 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f 6180a06bbc99fd9114b8db4be6c4d46e40f046ef git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 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00:13:13"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["drivers/net/ethernet/microsoft/mana/hw_channel.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"a201c66edf2ebc6cfdc3813a889ba20fecebfae3","status":"affected","version":"ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f","versionType":"git"},{"lessThan":"70ad2dff8d052a85dfef15715b531f38a29108cf","status":"affected","version":"ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f","versionType":"git"},{"lessThan":"566f42fb67a7ebfed6650e407e5b72e6b3e83bf7","status":"affected","version":"ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f","versionType":"git"},{"lessThan":"6180a06bbc99fd9114b8db4be6c4d46e40f046ef","status":"affected","version":"ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f","versionType":"git"},{"lessThan":"09ec063d87c2dd3fa6f3561361a017bd882e9f37","status":"affected","version":"ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f","versionType":"git"},{"lessThan":"3c4db56ccd13dd020fbf43afabaee74a40ec75e4","status":"affected","version":"ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f","versionType":"git"},{"lessThan":"35f0f0a2536a4d604b4dbad92c85c4a8fdebb870","status":"affected","version":"ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["drivers/net/ethernet/microsoft/mana/hw_channel.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"5.13"},{"lessThan":"5.13","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"5.15.*","status":"unaffected","version":"5.15.209","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.175","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.142","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.92","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.34","versionType":"semver"},{"lessThanOrEqual":"7.0.*","status":"unaffected","version":"7.0.11","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.15.209","versionStartIncluding":"5.13","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.175","versionStartIncluding":"5.13","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.142","versionStartIncluding":"5.13","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.92","versionStartIncluding":"5.13","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.34","versionStartIncluding":"5.13","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.0.11","versionStartIncluding":"5.13","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1","versionStartIncluding":"5.13","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: mana: Fix TOCTOU double-fetch of hwc_msg_id from DMA buffer\n\nIn mana_hwc_rx_event_handler(), resp->response.hwc_msg_id is read from\nDMA-coherent memory and bounds-checked, then mana_hwc_handle_resp()\nre-reads the same field from the same DMA buffer for test_bit() and\npointer arithmetic.\n\nDMA-coherent memory is mapped uncacheable on x86 and is shared,\nunencrypted, in Confidential VMs (SEV-SNP/TDX), so each load goes\ndirectly to host-visible memory. A H/W can modify the value\nbetween the check and the use, bypassing the bounds validation.\n\nFix this by reading hwc_msg_id exactly once using READ_ONCE() into a\nstack-local variable in mana_hwc_rx_event_handler(), and passing the\nvalidated value as a parameter to mana_hwc_handle_resp()."}],"metrics":[{"cvssV3_1":{"baseScore":9.3,"baseSeverity":"CRITICAL","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H","version":"3.1"}}],"providerMetadata":{"dateUpdated":"2026-07-20T13:42:37.820Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/a201c66edf2ebc6cfdc3813a889ba20fecebfae3"},{"url":"https://git.kernel.org/stable/c/70ad2dff8d052a85dfef15715b531f38a29108cf"},{"url":"https://git.kernel.org/stable/c/566f42fb67a7ebfed6650e407e5b72e6b3e83bf7"},{"url":"https://git.kernel.org/stable/c/6180a06bbc99fd9114b8db4be6c4d46e40f046ef"},{"url":"https://git.kernel.org/stable/c/09ec063d87c2dd3fa6f3561361a017bd882e9f37"},{"url":"https://git.kernel.org/stable/c/3c4db56ccd13dd020fbf43afabaee74a40ec75e4"},{"url":"https://git.kernel.org/stable/c/35f0f0a2536a4d604b4dbad92c85c4a8fdebb870"}],"title":"net: mana: Fix TOCTOU double-fetch of hwc_msg_id from DMA buffer","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-64034","datePublished":"2026-07-19T15:39:23.470Z","dateReserved":"2026-07-19T07:54:57.028Z","dateUpdated":"2026-07-20T13:42:37.820Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-07-19 16:17:43","lastModifiedDate":"2026-07-20 15:17:04","problem_types":[],"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H","baseScore":9.3,"baseSeverity":"CRITICAL","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"CHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":2.5,"impactScore":6}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"64034","Ordinal":"1","Title":"net: mana: Fix TOCTOU double-fetch of hwc_msg_id from DMA buffer","CVE":"CVE-2026-64034","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"64034","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: mana: Fix TOCTOU double-fetch of hwc_msg_id from DMA buffer\n\nIn mana_hwc_rx_event_handler(), resp->response.hwc_msg_id is read from\nDMA-coherent memory and bounds-checked, then mana_hwc_handle_resp()\nre-reads the same field from the same DMA buffer for test_bit() and\npointer arithmetic.\n\nDMA-coherent memory is mapped uncacheable on x86 and is shared,\nunencrypted, in Confidential VMs (SEV-SNP/TDX), so each load goes\ndirectly to host-visible memory. A H/W can modify the value\nbetween the check and the use, bypassing the bounds validation.\n\nFix this by reading hwc_msg_id exactly once using READ_ONCE() into a\nstack-local variable in mana_hwc_rx_event_handler(), and passing the\nvalidated value as a parameter to mana_hwc_handle_resp().","Type":"Description","Title":"net: mana: Fix TOCTOU double-fetch of hwc_msg_id from DMA buffer"}]}}}