{"id":"CVE-2026-89969","summary":"nvmet-tcp: fix out-of-bounds write when receiving an over-long PDU","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnvmet-tcp: fix out-of-bounds write when receiving an over-long PDU\n\nnvmet_tcp_try_recv_pdu() reads a PDU header into the fixed 128-byte\nqueue-\u003epdu union, then computes the remaining payload length as\n\n\tqueue-\u003eleft = hdr-\u003ehlen - queue-\u003eoffset + hdgst;\n\nand reads that many more bytes into &queue-\u003epdu + queue-\u003eoffset, without\never bounding the result against sizeof(queue-\u003epdu).\n\nA struct nvme_tcp_icreq_pdu is itself 128 bytes, exactly the size of the\nunion. Once a header digest has been negotiated (hdgst = 4), a second\nICReq passes the hlen == nvmet_tcp_pdu_size() check but yields\nqueue-\u003eleft = 128 - 8 + 4 = 124, so bytes 8..132 are written into the\n128-byte buffer -- 4 bytes past its end, over queue-\u003ehdr_digest and\nqueue-\u003edata_digest. Those bytes are attacker-controlled (an ICReq\ncarries no digest), and the duplicate ICReq is only rejected later,\nafter the overflow. A remote unauthenticated host can thus corrupt\nkernel memory adjacent to the receive buffer.\n\nReject any PDU whose declared length would read past the end of\nqueue-\u003epdu before the second recv.","modified":"2026-09-17T03:47:28.569783541Z","published":"2026-09-16T10:32:49.603Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89969.json"},"references":[{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"},{"type":"WEB","url":"https://git.kernel.org/stable/c/14cc5a7e77731497d5bea70f3bb05df7eda982e4"},{"type":"WEB","url":"https://git.kernel.org/stable/c/3a385e0c39efbe34db8edd95900c123113ae3450"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4f84d42c53c49557fb1ef285c683b0a81b576c74"},{"type":"WEB","url":"https://git.kernel.org/stable/c/58dc6035b79c4c73c0cbf9ec9f68a7f117b2b3e6"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a3f0bcfbaf3312a5754d1ce020a07d394669eb25"},{"type":"WEB","url":"https://git.kernel.org/stable/c/cf5f39d2b58f97e0cd1829c4a6aeef17f1607cca"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d95d342bc0ea82dc79e6362b2f1f997431750e4c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/dbc4acbdb3ca8c81441368ad7409b8f77d4de8f6"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89969.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89969"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"872d26a391da92ed8f0c0f5cb5fef428067b7f30"},{"fixed":"a3f0bcfbaf3312a5754d1ce020a07d394669eb25"},{"fixed":"4f84d42c53c49557fb1ef285c683b0a81b576c74"},{"fixed":"58dc6035b79c4c73c0cbf9ec9f68a7f117b2b3e6"},{"fixed":"cf5f39d2b58f97e0cd1829c4a6aeef17f1607cca"},{"fixed":"3a385e0c39efbe34db8edd95900c123113ae3450"},{"fixed":"dbc4acbdb3ca8c81441368ad7409b8f77d4de8f6"},{"fixed":"d95d342bc0ea82dc79e6362b2f1f997431750e4c"},{"fixed":"14cc5a7e77731497d5bea70f3bb05df7eda982e4"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89969.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.0.0"},{"fixed":"5.10.270"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.221"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.188"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.157"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.110"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.51"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.5"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89969.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}]}