{"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"}}}}