{"id":"CVE-2026-64268","state":"PUBLISHED","title":"RDMA/siw: bound Read Response placement to the RREAD length","description":"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.","publishedAt":"2026-07-25T08:49:16.336Z","updatedAt":"2026-10-19T20:28:16.936Z","severity":{"score":9.8,"label":"Critical","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"8b6a361b8c482f22ac99c3273285ff16b23fba91","status":"affected","lessThan":"a31b6d18ded3cc32d9ee85a6ff0726d4274887b2","versionType":"git"},{"version":"8b6a361b8c482f22ac99c3273285ff16b23fba91","status":"affected","lessThan":"595e6537ad1a210da32cbb9a7f91aa73090915ba","versionType":"git"},{"version":"8b6a361b8c482f22ac99c3273285ff16b23fba91","status":"affected","lessThan":"3ef7e052cbd05a8b13a51a07b185a39ec93ee1cf","versionType":"git"},{"version":"8b6a361b8c482f22ac99c3273285ff16b23fba91","status":"affected","lessThan":"b2e26c955f8dd7e8d3f16c858db05245ea4fa817","versionType":"git"},{"version":"8b6a361b8c482f22ac99c3273285ff16b23fba91","status":"affected","lessThan":"6bc89f34a4597f9f6d41f7a60c67a3153bfe8851","versionType":"git"},{"version":"8b6a361b8c482f22ac99c3273285ff16b23fba91","status":"affected","lessThan":"423a78ff7928c2601013f73ec6d896f5597d0df5","versionType":"git"},{"version":"8b6a361b8c482f22ac99c3273285ff16b23fba91","status":"affected","lessThan":"75c93cd3c421890f49ea93f0b978b9b7bb10e5e3","versionType":"git"},{"version":"8b6a361b8c482f22ac99c3273285ff16b23fba91","status":"affected","lessThan":"7d29f7e9dbd844cae4d3e559cf78324b9642fd6b","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/infiniband/sw/siw/siw_qp_rx.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.3","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.3","versionType":"semver"},{"version":"5.10.261","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.212","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.96","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.39","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.4","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/infiniband/sw/siw/siw_qp_rx.c"]}],"references":["https://git.kernel.org/stable/c/a31b6d18ded3cc32d9ee85a6ff0726d4274887b2","https://git.kernel.org/stable/c/595e6537ad1a210da32cbb9a7f91aa73090915ba","https://git.kernel.org/stable/c/3ef7e052cbd05a8b13a51a07b185a39ec93ee1cf","https://git.kernel.org/stable/c/b2e26c955f8dd7e8d3f16c858db05245ea4fa817","https://git.kernel.org/stable/c/6bc89f34a4597f9f6d41f7a60c67a3153bfe8851","https://git.kernel.org/stable/c/423a78ff7928c2601013f73ec6d896f5597d0df5","https://git.kernel.org/stable/c/75c93cd3c421890f49ea93f0b978b9b7bb10e5e3","https://git.kernel.org/stable/c/7d29f7e9dbd844cae4d3e559cf78324b9642fd6b"],"weaknesses":["CWE-787"],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/64xxx/CVE-2026-64268.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-64268","state":"PUBLISHED","datePublished":"2026-07-25T08:49:16.336Z","dateUpdated":"2026-10-19T20:28:16.936Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-19T15:36:31.775Z"},"containers":{"cna":{"title":"RDMA/siw: bound Read Response placement to the RREAD length","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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"8b6a361b8c482f22ac99c3273285ff16b23fba91","status":"affected","lessThan":"a31b6d18ded3cc32d9ee85a6ff0726d4274887b2","versionType":"git"},{"version":"8b6a361b8c482f22ac99c3273285ff16b23fba91","status":"affected","lessThan":"595e6537ad1a210da32cbb9a7f91aa73090915ba","versionType":"git"},{"version":"8b6a361b8c482f22ac99c3273285ff16b23fba91","status":"affected","lessThan":"3ef7e052cbd05a8b13a51a07b185a39ec93ee1cf","versionType":"git"},{"version":"8b6a361b8c482f22ac99c3273285ff16b23fba91","status":"affected","lessThan":"b2e26c955f8dd7e8d3f16c858db05245ea4fa817","versionType":"git"},{"version":"8b6a361b8c482f22ac99c3273285ff16b23fba91","status":"affected","lessThan":"6bc89f34a4597f9f6d41f7a60c67a3153bfe8851","versionType":"git"},{"version":"8b6a361b8c482f22ac99c3273285ff16b23fba91","status":"affected","lessThan":"423a78ff7928c2601013f73ec6d896f5597d0df5","versionType":"git"},{"version":"8b6a361b8c482f22ac99c3273285ff16b23fba91","status":"affected","lessThan":"75c93cd3c421890f49ea93f0b978b9b7bb10e5e3","versionType":"git"},{"version":"8b6a361b8c482f22ac99c3273285ff16b23fba91","status":"affected","lessThan":"7d29f7e9dbd844cae4d3e559cf78324b9642fd6b","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/infiniband/sw/siw/siw_qp_rx.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.3","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.3","versionType":"semver"},{"version":"5.10.261","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.212","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.96","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.39","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.4","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/infiniband/sw/siw/siw_qp_rx.c"]}],"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"}],"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."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-17T04:52:22.293Z"},"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"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-64268","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:38:06.422675Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-787","lang":"en","type":"CWE","description":"CWE-787 Out-of-bounds Write"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T20:28:16.936Z"}}]}}}