{"id":"CVE-2026-64018","state":"PUBLISHED","title":"net: mana: validate rx_req_idx to prevent out-of-bounds array access","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: mana: validate rx_req_idx to prevent out-of-bounds array access\n\nIn mana_hwc_rx_event_handler(), rx_req_idx is derived from\nsge->address in DMA-coherent memory. In Confidential VMs\n(SEV-SNP/TDX), this memory is shared unencrypted and HW can modify\nWQE contents at any time. No bounds check exists on rx_req_idx,\nwhich can lead to an out-of-bounds access into reqs[].\n\nAdd bounds check on rx_req_idx in mana_hwc_rx_event_handler() before\nusing it to index the reqs[] array.","publishedAt":"2026-07-19T15:39:12.704Z","updatedAt":"2026-10-19T20:28:08.648Z","severity":{"score":9.3,"label":"Critical","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f","status":"affected","lessThan":"5ddc715324badd7f2641bc177db1d027b402adae","versionType":"git"},{"version":"ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f","status":"affected","lessThan":"ff1d5af207bcea857d45fe81505f1bc4b29eaef0","versionType":"git"},{"version":"ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f","status":"affected","lessThan":"01f7f893d5e1baae995beeb86cd0f3e6bb2a3b01","versionType":"git"},{"version":"ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f","status":"affected","lessThan":"763a372d344fb12fae566d36ddb46e92454ad58c","versionType":"git"},{"version":"ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f","status":"affected","lessThan":"fa627a5eaa83fc0261f44ef3769693b886ca6e27","versionType":"git"},{"version":"ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f","status":"affected","lessThan":"355e9f2b2a7887ca38100127989af3e422ba71d0","versionType":"git"},{"version":"ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f","status":"affected","lessThan":"b809d0409991b75a6cff846a5ac27c3062953f84","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ethernet/microsoft/mana/hw_channel.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.13","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.13","versionType":"semver"},{"version":"5.15.209","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.175","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.142","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.92","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.34","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.11","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ethernet/microsoft/mana/hw_channel.c"]}],"references":["https://git.kernel.org/stable/c/5ddc715324badd7f2641bc177db1d027b402adae","https://git.kernel.org/stable/c/ff1d5af207bcea857d45fe81505f1bc4b29eaef0","https://git.kernel.org/stable/c/01f7f893d5e1baae995beeb86cd0f3e6bb2a3b01","https://git.kernel.org/stable/c/763a372d344fb12fae566d36ddb46e92454ad58c","https://git.kernel.org/stable/c/fa627a5eaa83fc0261f44ef3769693b886ca6e27","https://git.kernel.org/stable/c/355e9f2b2a7887ca38100127989af3e422ba71d0","https://git.kernel.org/stable/c/b809d0409991b75a6cff846a5ac27c3062953f84"],"weaknesses":["CWE-125"],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/64xxx/CVE-2026-64018.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-64018","state":"PUBLISHED","datePublished":"2026-07-19T15:39:12.704Z","dateUpdated":"2026-10-19T20:28:08.648Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-19T07:54:57.027Z"},"containers":{"cna":{"title":"net: mana: validate rx_req_idx to prevent out-of-bounds array access","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: mana: validate rx_req_idx to prevent out-of-bounds array access\n\nIn mana_hwc_rx_event_handler(), rx_req_idx is derived from\nsge->address in DMA-coherent memory. In Confidential VMs\n(SEV-SNP/TDX), this memory is shared unencrypted and HW can modify\nWQE contents at any time. No bounds check exists on rx_req_idx,\nwhich can lead to an out-of-bounds access into reqs[].\n\nAdd bounds check on rx_req_idx in mana_hwc_rx_event_handler() before\nusing it to index the reqs[] array."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f","status":"affected","lessThan":"5ddc715324badd7f2641bc177db1d027b402adae","versionType":"git"},{"version":"ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f","status":"affected","lessThan":"ff1d5af207bcea857d45fe81505f1bc4b29eaef0","versionType":"git"},{"version":"ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f","status":"affected","lessThan":"01f7f893d5e1baae995beeb86cd0f3e6bb2a3b01","versionType":"git"},{"version":"ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f","status":"affected","lessThan":"763a372d344fb12fae566d36ddb46e92454ad58c","versionType":"git"},{"version":"ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f","status":"affected","lessThan":"fa627a5eaa83fc0261f44ef3769693b886ca6e27","versionType":"git"},{"version":"ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f","status":"affected","lessThan":"355e9f2b2a7887ca38100127989af3e422ba71d0","versionType":"git"},{"version":"ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f","status":"affected","lessThan":"b809d0409991b75a6cff846a5ac27c3062953f84","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ethernet/microsoft/mana/hw_channel.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.13","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.13","versionType":"semver"},{"version":"5.15.209","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.175","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.142","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.92","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.34","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.11","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ethernet/microsoft/mana/hw_channel.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/5ddc715324badd7f2641bc177db1d027b402adae"},{"url":"https://git.kernel.org/stable/c/ff1d5af207bcea857d45fe81505f1bc4b29eaef0"},{"url":"https://git.kernel.org/stable/c/01f7f893d5e1baae995beeb86cd0f3e6bb2a3b01"},{"url":"https://git.kernel.org/stable/c/763a372d344fb12fae566d36ddb46e92454ad58c"},{"url":"https://git.kernel.org/stable/c/fa627a5eaa83fc0261f44ef3769693b886ca6e27"},{"url":"https://git.kernel.org/stable/c/355e9f2b2a7887ca38100127989af3e422ba71d0"},{"url":"https://git.kernel.org/stable/c/b809d0409991b75a6cff846a5ac27c3062953f84"}],"metrics":[{"cvssV3_1":{"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"},"scenarios":[{"lang":"en","value":"AV:L - The bug is reached via MSI-driven hardware completion processing in the MANA HWC control path (not netdev packet receive), triggered when the Azure hypervisor/host tampers with guest-visible DMA-coherent WQE memory on the same physical compute node.\nAC:L - A malicious host or NIC firmware that can modify shared unencrypted DMA buffers controls both the forged sge->address and the timing of HWC RX completions, allowing reliable out-of-bounds indexing without winning a race or depending on guest state.\nPR:N - Exploitation requires no privileges on the victim guest VM; the attacker operates from the Azure hypervisor/host side by modifying DMA-coherent memory that the guest kernel trusts during HWC response handling.\nUI:N - No victim user action is required; exploitation occurs automatically when the driver processes a hardware completion event on the HWC receive queue.\nS:C - In Confidential VMs the guest relies on host isolation guarantees, but shared unencrypted DMA memory lets a hostile hypervisor cross that CVM security boundary to corrupt guest kernel memory and confidentiality.\nC:H - An out-of-bounds rx_req_idx yields a corrupted hwc_work_request whose buf_va is dereferenced and copied via memcpy in mana_hwc_handle_resp(), enabling arbitrary kernel memory disclosure.\nI:H - The out-of-bounds hwc_work_request supplies attacker-controlled pointers and SGE fields used to repost RX WQEs via mana_hwc_post_rx_wqe(), enabling kernel heap corruption and exploitable memory writes.\nA:H - Indexing reqs[] out of bounds with attacker-controlled values can dereference invalid kernel pointers and corrupt adjacent heap objects, causing kernel oops/panic and denial of service."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:38:15.556Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"5.15.209"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"6.1.175"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"6.6.142"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"6.12.92"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"6.18.34"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"7.0.11"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"7.1"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-64018","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:35:22.459884Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-125","lang":"en","type":"CWE","description":"CWE-125 Out-of-bounds Read"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T20:28:08.648Z"}}]}}}