{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-64268", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T15:36:31.775Z", "datePublished": "2026-07-25T08:49:16.336Z", "dateUpdated": "2026-08-17T04:52:22.293Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T04:52:22.293Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/siw: bound Read Response placement to the RREAD length\n\nIn drivers/infiniband/sw/siw/siw_qp_rx.c, siw_proc_rresp() places each\ninbound Read Response DDP segment at sge->laddr + wqe->processed and then\naccumulates wqe->processed, but it never checks the running total against\nthe sink buffer length on continuation segments. siw_check_sge() resolves\nand validates the sink memory only on the first fragment (the if (!*mem)\nbranch), and siw_rresp_check_ntoh() compares the cumulative length against\nwqe->bytes only on the final segment (the !frx->more_ddp_segs guard).\n\nA connected siw peer that answers an outstanding RREAD with Read Response\nsegments that keep the DDP Last flag clear, carrying more total payload\nthan the RREAD requested, drives wqe->processed past the validated sink\nbuffer; the next siw_rx_data() call writes out of bounds at\nsge->laddr + wqe->processed. siw runs iWARP over ordinary routable TCP,\nso the peer is the remote end of an established RDMA connection and needs\nno local privilege.\n\nBound every segment before placement, exactly as siw_proc_send() and\nsiw_proc_write() already do for their tagged and untagged paths, and\nterminate the connection with a base-or-bounds DDP error when the\nRead Response would overrun the sink buffer.\n\nThis is the second receive-path length fix for this file. A separate\nchange rejects an MPA FPDU length that underflows the per-fragment\nremainder in the header decode; that guard does not cover this case,\nbecause here each individual segment length is self-consistent and only\nthe accumulated placement offset overruns the buffer." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL" }, "scenarios": [ { "lang": "en", "value": "AV:N - siw carries iWARP over ordinary routable TCP, and the vulnerable receive callback processes crafted Read Response FPDUs from the remote endpoint of an established RDMA connection.\nAC:L - The peer learns the sink tag, address, and length from the RREAD and can deterministically send oversized continuation segments; no race or uncontrollable condition is required.\nPR:N - The MPA/siw data path performs no credential or capability check on the connected peer, and an unauthenticated RDMA service can accept the connection and issue attacker-induced RREADs.\nUI:N - The overflow is triggered through an automated RDMA protocol exchange and requires no human action.\nS:U - The corruption compromises resources within the affected host's kernel security authority and does not inherently cross a VM, IOMMU, or other security boundary.\nC:H - The global DMA/KVA sink case exposes the sink address and permits attacker-controlled kernel memory corruption, which can enable control-flow hijacking and arbitrary kernel-memory disclosure.\nI:H - Attacker-chosen response bytes are written beyond the validated sink into adjacent kernel memory, providing an exploitable out-of-bounds write capable of modifying objects or achieving kernel code execution.\nA:H - The overwrite can corrupt critical kernel objects or reach invalid memory, causing an oops or panic; bounded FRWR sinks still permit connection-terminating denial of service." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/infiniband/sw/siw/siw_qp_rx.c" ], "versions": [ { "version": "8b6a361b8c482f22ac99c3273285ff16b23fba91", "lessThan": "a31b6d18ded3cc32d9ee85a6ff0726d4274887b2", "status": "affected", "versionType": "git" }, { "version": "8b6a361b8c482f22ac99c3273285ff16b23fba91", "lessThan": "595e6537ad1a210da32cbb9a7f91aa73090915ba", "status": "affected", "versionType": "git" }, { "version": "8b6a361b8c482f22ac99c3273285ff16b23fba91", "lessThan": "3ef7e052cbd05a8b13a51a07b185a39ec93ee1cf", "status": "affected", "versionType": "git" }, { "version": "8b6a361b8c482f22ac99c3273285ff16b23fba91", "lessThan": "b2e26c955f8dd7e8d3f16c858db05245ea4fa817", "status": "affected", "versionType": "git" }, { "version": "8b6a361b8c482f22ac99c3273285ff16b23fba91", "lessThan": "6bc89f34a4597f9f6d41f7a60c67a3153bfe8851", "status": "affected", "versionType": "git" }, { "version": "8b6a361b8c482f22ac99c3273285ff16b23fba91", "lessThan": "423a78ff7928c2601013f73ec6d896f5597d0df5", "status": "affected", "versionType": "git" }, { "version": "8b6a361b8c482f22ac99c3273285ff16b23fba91", "lessThan": "75c93cd3c421890f49ea93f0b978b9b7bb10e5e3", "status": "affected", "versionType": "git" }, { "version": "8b6a361b8c482f22ac99c3273285ff16b23fba91", "lessThan": "7d29f7e9dbd844cae4d3e559cf78324b9642fd6b", "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/infiniband/sw/siw/siw_qp_rx.c" ], "versions": [ { "version": "5.3", "status": "affected" }, { "version": "0", "lessThan": "5.3", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.261", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.212", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.178", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.145", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.96", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.39", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.4", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "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": "5.3", "versionEndExcluding": "5.10.261" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.3", "versionEndExcluding": "5.15.212" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.3", "versionEndExcluding": "6.1.178" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.3", "versionEndExcluding": "6.6.145" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.3", "versionEndExcluding": "6.12.96" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.3", "versionEndExcluding": "6.18.39" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.3", "versionEndExcluding": "7.1.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.3", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/a31b6d18ded3cc32d9ee85a6ff0726d4274887b2" }, { "url": "https://git.kernel.org/stable/c/595e6537ad1a210da32cbb9a7f91aa73090915ba" }, { "url": "https://git.kernel.org/stable/c/3ef7e052cbd05a8b13a51a07b185a39ec93ee1cf" }, { "url": "https://git.kernel.org/stable/c/b2e26c955f8dd7e8d3f16c858db05245ea4fa817" }, { "url": "https://git.kernel.org/stable/c/6bc89f34a4597f9f6d41f7a60c67a3153bfe8851" }, { "url": "https://git.kernel.org/stable/c/423a78ff7928c2601013f73ec6d896f5597d0df5" }, { "url": "https://git.kernel.org/stable/c/75c93cd3c421890f49ea93f0b978b9b7bb10e5e3" }, { "url": "https://git.kernel.org/stable/c/7d29f7e9dbd844cae4d3e559cf78324b9642fd6b" } ], "title": "RDMA/siw: bound Read Response placement to the RREAD length", "x_generator": { "engine": "bippy-1.2.0" } } } }