{"id":"CVE-2026-80789","revision":"d4f18d1daebb4a2ca01aac6a0deff263","records":[{"revision":"d4f18d1daebb4a2ca01aac6a0deff263","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-80789","aliases":[],"title":"nvmet-tcp: bound SGL data length before allocating command buffers","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnvmet-tcp: bound SGL data length before allocating command buffers\n\nnvmet_tcp_map_data() reads the host-controlled 32-bit sgl->length\nand, for the in-capsule offset descriptor (type 0x01), checks it\nagainst port->inline_data_size before use. Any other SGL descriptor\ntype -- including the non-inline transport SGL data-block descriptor\n(type (NVME_TRANSPORT_SGL_DATA_DESC << 4) | NVME_SGL_FMT_TRANSPORT_A,\nthe type a real host uses for out-of-capsule writes) skips that check\nentirely and falls straight through to:\n\n\tcmd->req.sg = sgl_alloc(len, GFP_KERNEL, &cmd->req.sg_cnt);\n\nwith len taken directly from the wire, unbounded up to 4 GiB.\n\nnvmet_req_init() only parses the command and never inspects\nsgl->length, and nvmet_check_transfer_len() -- the only other place\ntransfer_len is validated -- runs later, from req->execute(), after\nthe allocation has already happened. For a write command the target\nresponds with an R2T and parks the command waiting for the host to\nsend the data; if the host (or an unauthenticated peer that simply\nnever follows up) never does, the sgl_alloc() buffer stays resident\nfor the life of the command. NVMe/TCP has no mandatory authentication\nin the default configuration, so any peer able to reach the target\nportal and complete a Fabrics connect can drive this with a single\ncrafted command, repeatable across queues and connections for\namplification. This is unbounded kernel memory allocation\ntriggered by a remote, effectively unauthenticated peer.\n\nValidate len against the same NVMET_TCP_MAXH2CDATA ceiling this file\nalready uses to bound per-PDU H2C data, for every SGL descriptor type,\nbefore doing any allocation. This closes the gap for the non-inline\ndescriptor while leaving the existing, tighter inline_data_size check\nin place for the in-capsule case.\n\nRuntime-verified on a v6.19 KASAN stand: with this bound in place, a\ncrafted write command carrying an oversized non-inline SGL length is\nrejected before sgl_alloc() runs, where the same request previously\ndrove an unbounded ~256 MiB kernel allocation (up to 4 GiB) that\nstayed resident pending an R2T the host never satisfies.","state":0,"publishedAt":"2026-09-04T15:13:01.161+00:00","modifiedAt":"2026-10-19T08:43:42.439+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"drivers/nvme/target/tcp.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"872d26a391da92ed8f0c0f5cb5fef428067b7f30\",\n                            \"lessThan\": \"f6e51b09cbaa5f6f6e6a3a9dafa666f76c37aab5\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"872d26a391da92ed8f0c0f5cb5fef428067b7f30\",\n                            \"lessThan\": \"f63e89a0310264264923f84406dea05fe752de62\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"872d26a391da92ed8f0c0f5cb5fef428067b7f30\",\n                            \"lessThan\": \"0952541b153e258b99d39cdb03ea6919fdeb41d0\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"872d26a391da92ed8f0c0f5cb5fef428067b7f30\",\n                            \"lessThan\": \"25ad03d5c0e858c4b63f1e4b6d461d2af1b30b22\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"872d26a391da92ed8f0c0f5cb5fef428067b7f30\",\n                            \"lessThan\": \"d2acc96c528d589f5827cfb90e8e9229dd9d8cb4\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"872d26a391da92ed8f0c0f5cb5fef428067b7f30\",\n                            \"lessThan\": \"6d27199ebe8cb223022150f74be13f154a964474\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"872d26a391da92ed8f0c0f5cb5fef428067b7f30\",\n                            \"lessThan\": \"14dbe37681a6a7e346fc147bb363ec7cca3180a0\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"872d26a391da92ed8f0c0f5cb5fef428067b7f30\",\n                            \"lessThan\": \"d895e66628f939edbb98608f6e033d3d39e6e546\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"872d26a391da92ed8f0c0f5cb5fef428067b7f30\",\n                            \"lessThan\": \"4a3f00262a044e8e15064b1a6860968bf0500bf4\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"drivers/nvme/target/tcp.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"5.0\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"5.0\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.10.269\",\n                            \"lessThanOrEqual\": \"5.10.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.220\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.187\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.156\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.106\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.47\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.1.11\",\n                            \"lessThanOrEqual\": \"7.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.1\",\n                            \"lessThanOrEqual\": \"7.2.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.3\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[],"references":["https://git.kernel.org/stable/c/f6e51b09cbaa5f6f6e6a3a9dafa666f76c37aab5","https://git.kernel.org/stable/c/f63e89a0310264264923f84406dea05fe752de62","https://git.kernel.org/stable/c/0952541b153e258b99d39cdb03ea6919fdeb41d0","https://git.kernel.org/stable/c/25ad03d5c0e858c4b63f1e4b6d461d2af1b30b22","https://git.kernel.org/stable/c/d2acc96c528d589f5827cfb90e8e9229dd9d8cb4","https://git.kernel.org/stable/c/6d27199ebe8cb223022150f74be13f154a964474","https://git.kernel.org/stable/c/14dbe37681a6a7e346fc147bb363ec7cca3180a0","https://git.kernel.org/stable/c/d895e66628f939edbb98608f6e033d3d39e6e546","https://git.kernel.org/stable/c/4a3f00262a044e8e15064b1a6860968bf0500bf4"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-80789","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-80789","identifiers":["CVE-2026-80789"]},"retained":false,"historicalAffected":[]}],"coverage":[]}