{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-64269", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T15:36:31.775Z", "datePublished": "2026-07-25T08:49:16.946Z", "dateUpdated": "2026-08-23T12:45:35.835Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-23T12:45:35.835Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/rtrs-srv: Bound RDMA-Write length to chunk size in rdma_write_sg\n\nWhen the server answers an RTRS READ, rdma_write_sg() builds the source\nscatter/gather entry for the IB_WR_RDMA_WRITE that returns data to the\npeer. Its length is taken directly from the wire descriptor:\n\n plist->length = le32_to_cpu(id->rd_msg->desc[0].len);\n\nrd_msg points into the chunk buffer that the remote peer filled via\nRDMA-WRITE-WITH-IMM (rtrs_srv_rdma_done() -> process_io_req() ->\nprocess_read()), so desc[0].len is attacker-controlled and, before this\nchange, was only rejected when zero. The source address is the fixed\nchunk start (dma_addr[msg_id]) and the source lkey is the PD-wide\nlocal_dma_lkey, which is not tied to the chunk's MR mapping, so the verbs\nlayer does not constrain the transfer length to max_chunk_size. msg_id\nand off are bounded against queue_depth and max_chunk_size in\nrtrs_srv_rdma_done(), but desc[0].len is a separate field that was not\nchecked against the chunk size.\n\nA peer that advertises desc[0].len larger than max_chunk_size can make\nthe posted RDMA write read past the chunk's mapped region. The resulting\nbehaviour depends on the IOMMU configuration: with no IOMMU or in\npassthrough mode the read may extend into memory adjacent to the chunk\nand be returned to the peer, which can disclose host memory; with a\ntranslating IOMMU the out-of-range access is expected to fault and abort\nthe connection. In either case the transfer exceeds what the protocol\npermits and is driven by a remote peer.\n\nReject a descriptor length above max_chunk_size, mirroring the existing\noff >= max_chunk_size bound in rtrs_srv_rdma_done(). Legitimate clients\ndo not exceed it: the client sets desc[0].len to its MR length, which is\ncapped at the negotiated max_io_size (max_chunk_size - MAX_HDR_SIZE)." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H", "baseScore": 9.1, "baseSeverity": "CRITICAL" }, "scenarios": [ { "lang": "en", "value": "AV:N - RTRS accepts network connections over routable RDMA transports including RoCE and iWARP, and the malicious descriptor is supplied by a remote peer.\nAC:L - The peer directly controls the descriptor length and destination buffer; no race, timing, or victim-controlled state is required in no-IOMMU, passthrough, or software-RDMA deployments.\nPR:N - The handshake validates protocol fields but performs no credential, capability, or authentication check before publishing chunk rkeys and accepting I/O requests.\nUI:N - After connecting, the attacker can submit the crafted RDMA READ request without any victim action.\nS:U - The vulnerable RTRS module and affected host memory remain within the kernel's security authority; a translating IOMMU prevents rather than permits crossing its isolation boundary.\nC:H - The PD-wide local DMA key does not constrain the attacker-supplied transfer length, permitting a broad out-of-bounds read of adjacent host memory that is returned to the peer.\nI:N - The malformed operation reads server memory and writes it only to the peer's registered destination; it provides no server-side memory-write primitive.\nA:H - Software-RDMA can CPU-copy through invalid pages and oops or crash, while hardware or IOMMU faults can abort paths. An unauthenticated peer can trigger the condition repeatedly." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/infiniband/ulp/rtrs/rtrs-srv.c" ], "versions": [ { "version": "9cb837480424e78ed585376f944088246685aec3", "lessThan": "a35b7a8728a53ddc80b323970689fa5985816836", "status": "affected", "versionType": "git" }, { "version": "9cb837480424e78ed585376f944088246685aec3", "lessThan": "68c09762172f6224e9ddf9b0a60bacbb36e443eb", "status": "affected", "versionType": "git" }, { "version": "9cb837480424e78ed585376f944088246685aec3", "lessThan": "6cada540150894e81042a0ae0c796a21a9a877da", "status": "affected", "versionType": "git" }, { "version": "9cb837480424e78ed585376f944088246685aec3", "lessThan": "2912f3d40355dabc08fdbaaf2764d02445fe88dc", "status": "affected", "versionType": "git" }, { "version": "9cb837480424e78ed585376f944088246685aec3", "lessThan": "6f40246f4312fdbab5a13cc440adebf95eb2aa66", "status": "affected", "versionType": "git" }, { "version": "9cb837480424e78ed585376f944088246685aec3", "lessThan": "5a45d0aa1fa50a333ce5763ade744e2d89838667", "status": "affected", "versionType": "git" }, { "version": "9cb837480424e78ed585376f944088246685aec3", "lessThan": "da3e44add94b05dfde56f898421922f5cf35705f", "status": "affected", "versionType": "git" }, { "version": "9cb837480424e78ed585376f944088246685aec3", "lessThan": "963af8d97a8c6a117134a8d0db1415e0489200b1", "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/ulp/rtrs/rtrs-srv.c" ], "versions": [ { "version": "5.8", "status": "affected" }, { "version": "0", "lessThan": "5.8", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.266", "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": "5.8", "versionEndExcluding": "5.10.266" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.8", "versionEndExcluding": "5.15.212" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.8", "versionEndExcluding": "6.1.178" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.8", "versionEndExcluding": "6.6.145" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.8", "versionEndExcluding": "6.12.96" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.8", "versionEndExcluding": "6.18.39" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.8", "versionEndExcluding": "7.1.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.8", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/a35b7a8728a53ddc80b323970689fa5985816836" }, { "url": "https://git.kernel.org/stable/c/68c09762172f6224e9ddf9b0a60bacbb36e443eb" }, { "url": "https://git.kernel.org/stable/c/6cada540150894e81042a0ae0c796a21a9a877da" }, { "url": "https://git.kernel.org/stable/c/2912f3d40355dabc08fdbaaf2764d02445fe88dc" }, { "url": "https://git.kernel.org/stable/c/6f40246f4312fdbab5a13cc440adebf95eb2aa66" }, { "url": "https://git.kernel.org/stable/c/5a45d0aa1fa50a333ce5763ade744e2d89838667" }, { "url": "https://git.kernel.org/stable/c/da3e44add94b05dfde56f898421922f5cf35705f" }, { "url": "https://git.kernel.org/stable/c/963af8d97a8c6a117134a8d0db1415e0489200b1" } ], "title": "RDMA/rtrs-srv: Bound RDMA-Write length to chunk size in rdma_write_sg", "x_generator": { "engine": "bippy-1.2.0" } } } }