{"id":"CVE-2026-89480","state":"PUBLISHED","title":"nvme-tcp: reject a read that transferred too few bytes","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnvme-tcp: reject a read that transferred too few bytes\n\nnvme_tcp_recv_data() completes a request once the current C2HData PDU\nhas been consumed. Nothing compares the total bytes received against\nthe length the command asked for: struct nvme_tcp_request has no\nreceive-side counter, queue->data_remaining is per queue, and\nblk_mq_end_request() completes for blk_rq_bytes(rq) unconditionally\nwith no residual concept anywhere above.\n\nA controller can therefore answer a 4096-byte read with 512 bytes and\nhave it reported as a complete read; user space then gets 4096 bytes of\nwhich 3584 are whatever was already in the page. I reproduced that with\na test target.\n\nCount the bytes received and refuse to complete a successful read whose\ncount does not match, at the two NVME_TCP_F_DATA_SUCCESS paths and in\nnvme_tcp_process_nvme_cqe(). The success test shifts req->status right\nby one, because the driver keeps the wire value there and shifts it on\ncompletion, so the check must see what the completion path will see.\nOnly REQ_OP_READ is checked, because there the length comes from the\nsectors the request covers; a passthrough command is built by its\nsubmitter, which picks both command and buffer, so the kernel has\nnothing to compare against.","publishedAt":"2026-09-11T19:43:35.930Z","updatedAt":"2026-10-30T12:31:52.756Z","severity":{"score":7.5,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"3f2304f8c6d6ed97849057bd16fee99e434ca796","status":"affected","lessThan":"b674af31d044a86bd094ba8bb8f2bb92fb49aac5","versionType":"git"},{"version":"3f2304f8c6d6ed97849057bd16fee99e434ca796","status":"affected","lessThan":"a5c1bb0fb1bab2f24a081339c145870697f6d220","versionType":"git"},{"version":"3f2304f8c6d6ed97849057bd16fee99e434ca796","status":"affected","lessThan":"aa107e3a68f4af177d60f2d87679e7f67179a36c","versionType":"git"},{"version":"3f2304f8c6d6ed97849057bd16fee99e434ca796","status":"affected","lessThan":"fca3ebb63e5c82561cd9934365dcc0d068008006","versionType":"git"},{"version":"3f2304f8c6d6ed97849057bd16fee99e434ca796","status":"affected","lessThan":"99066cf9bba175f610ceb61a35f6fc9fbc33ff65","versionType":"git"},{"version":"3f2304f8c6d6ed97849057bd16fee99e434ca796","status":"affected","lessThan":"8a02ad98798fd01f51f648c1fdd8f3c9d07195d3","versionType":"git"},{"version":"3f2304f8c6d6ed97849057bd16fee99e434ca796","status":"affected","lessThan":"832a685efeb5d925ee7d30011d2dbe45f81447a3","versionType":"git"},{"version":"3f2304f8c6d6ed97849057bd16fee99e434ca796","status":"affected","lessThan":"7fa3f73f6c8ddc5f0425b50fb2a626a782ef7d12","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/nvme/host/tcp.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.0","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.0","versionType":"semver"},{"version":"5.10.273","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.221","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.188","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.157","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.109","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.50","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.4","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/nvme/host/tcp.c"]}],"references":["https://git.kernel.org/stable/c/b674af31d044a86bd094ba8bb8f2bb92fb49aac5","https://git.kernel.org/stable/c/a5c1bb0fb1bab2f24a081339c145870697f6d220","https://git.kernel.org/stable/c/aa107e3a68f4af177d60f2d87679e7f67179a36c","https://git.kernel.org/stable/c/fca3ebb63e5c82561cd9934365dcc0d068008006","https://git.kernel.org/stable/c/99066cf9bba175f610ceb61a35f6fc9fbc33ff65","https://git.kernel.org/stable/c/8a02ad98798fd01f51f648c1fdd8f3c9d07195d3","https://git.kernel.org/stable/c/832a685efeb5d925ee7d30011d2dbe45f81447a3","https://git.kernel.org/stable/c/7fa3f73f6c8ddc5f0425b50fb2a626a782ef7d12"],"weaknesses":[],"ingestedAt":"2026-10-30T12:50:04.827Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/89xxx/CVE-2026-89480.json","commit":"1f312381e38164a43607eebab851b151dd16861e","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-89480","state":"PUBLISHED","datePublished":"2026-09-11T19:43:35.930Z","dateUpdated":"2026-10-30T12:31:52.756Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-11T19:38:34.711Z"},"containers":{"cna":{"title":"nvme-tcp: reject a read that transferred too few bytes","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnvme-tcp: reject a read that transferred too few bytes\n\nnvme_tcp_recv_data() completes a request once the current C2HData PDU\nhas been consumed. Nothing compares the total bytes received against\nthe length the command asked for: struct nvme_tcp_request has no\nreceive-side counter, queue->data_remaining is per queue, and\nblk_mq_end_request() completes for blk_rq_bytes(rq) unconditionally\nwith no residual concept anywhere above.\n\nA controller can therefore answer a 4096-byte read with 512 bytes and\nhave it reported as a complete read; user space then gets 4096 bytes of\nwhich 3584 are whatever was already in the page. I reproduced that with\na test target.\n\nCount the bytes received and refuse to complete a successful read whose\ncount does not match, at the two NVME_TCP_F_DATA_SUCCESS paths and in\nnvme_tcp_process_nvme_cqe(). The success test shifts req->status right\nby one, because the driver keeps the wire value there and shifts it on\ncompletion, so the check must see what the completion path will see.\nOnly REQ_OP_READ is checked, because there the length comes from the\nsectors the request covers; a passthrough command is built by its\nsubmitter, which picks both command and buffer, so the kernel has\nnothing to compare against."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"3f2304f8c6d6ed97849057bd16fee99e434ca796","status":"affected","lessThan":"b674af31d044a86bd094ba8bb8f2bb92fb49aac5","versionType":"git"},{"version":"3f2304f8c6d6ed97849057bd16fee99e434ca796","status":"affected","lessThan":"a5c1bb0fb1bab2f24a081339c145870697f6d220","versionType":"git"},{"version":"3f2304f8c6d6ed97849057bd16fee99e434ca796","status":"affected","lessThan":"aa107e3a68f4af177d60f2d87679e7f67179a36c","versionType":"git"},{"version":"3f2304f8c6d6ed97849057bd16fee99e434ca796","status":"affected","lessThan":"fca3ebb63e5c82561cd9934365dcc0d068008006","versionType":"git"},{"version":"3f2304f8c6d6ed97849057bd16fee99e434ca796","status":"affected","lessThan":"99066cf9bba175f610ceb61a35f6fc9fbc33ff65","versionType":"git"},{"version":"3f2304f8c6d6ed97849057bd16fee99e434ca796","status":"affected","lessThan":"8a02ad98798fd01f51f648c1fdd8f3c9d07195d3","versionType":"git"},{"version":"3f2304f8c6d6ed97849057bd16fee99e434ca796","status":"affected","lessThan":"832a685efeb5d925ee7d30011d2dbe45f81447a3","versionType":"git"},{"version":"3f2304f8c6d6ed97849057bd16fee99e434ca796","status":"affected","lessThan":"7fa3f73f6c8ddc5f0425b50fb2a626a782ef7d12","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/nvme/host/tcp.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.0","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.0","versionType":"semver"},{"version":"5.10.273","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.221","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.188","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.157","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.109","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.50","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.4","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/nvme/host/tcp.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/b674af31d044a86bd094ba8bb8f2bb92fb49aac5"},{"url":"https://git.kernel.org/stable/c/a5c1bb0fb1bab2f24a081339c145870697f6d220"},{"url":"https://git.kernel.org/stable/c/aa107e3a68f4af177d60f2d87679e7f67179a36c"},{"url":"https://git.kernel.org/stable/c/fca3ebb63e5c82561cd9934365dcc0d068008006"},{"url":"https://git.kernel.org/stable/c/99066cf9bba175f610ceb61a35f6fc9fbc33ff65"},{"url":"https://git.kernel.org/stable/c/8a02ad98798fd01f51f648c1fdd8f3c9d07195d3"},{"url":"https://git.kernel.org/stable/c/832a685efeb5d925ee7d30011d2dbe45f81447a3"},{"url":"https://git.kernel.org/stable/c/7fa3f73f6c8ddc5f0425b50fb2a626a782ef7d12"}],"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:N","baseScore":7.5,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:N - C2HData is parsed on the nvme-tcp host socket path (nvme_tcp_data_ready -> nvme_tcp_try_recv -> nvme_tcp_recv_skb -> nvme_tcp_recv_data) over routable TCP (typically 4420). A malicious or compromised NVMe-oF target, or an on-path injector into the default-unencrypted stream, triggers it from the network.\nAC:L - nvme_tcp_handle_c2h_data() sets queue->data_remaining from the attacker-controlled PDU data_length with no comparison to req->data_len. A short or zero-length C2HData with NVME_TCP_F_DATA_SUCCESS, or a short C2HData plus a success CQE, completes the read every time; no race or layout dependence.\nPR:N - The attacker is the NVMe-oF peer and needs no host account or capability. NVMe/TCP is unauthenticated by default (DH-HMAC-CHAP and TLS are optional), so a malicious, compromised, or spoofed target can short any in-flight read once the fabrics connection exists.\nUI:N - NVMe-oF controllers are persistent boot/autoconnect configuration and are re-established by nvme_tcp_error_recovery(). Namespace scan, partition probe, udev, and mounted-filesystem readahead issue REQ_OP_READ from kernel work without further victim action at attack time.\nS:U - Leftover host page-cache and buddy-page contents are exposed to local readers of the same kernel's NVMe device. No VM, IOMMU, or sandbox boundary is crossed.\nC:H - blk_mq_end_request() completes the full blk_rq_bytes, so userspace and page cache see leftover destination-page bytes as valid data. Those pages are not zeroed; sibling CVE-2026-89481 showed they hold stale kernel data including struct page pointers. Leak size is attacker-chosen up to the whole I/O, including a 0-length SUCCESS PDU.\nI:N - The bug under-fills the bio and reports success; it does not write out of bounds, free an object, or give a kernel write/hijack primitive. Bytes the target does send are data a storage controller already controls, and leftover bytes are prior page contents rather than attacker-chosen writes.\nA:N - The vulnerable path completes the request as success with no oops, panic, hang, deadlock, or leak. Availability of the host kernel is unaffected; error recovery (-EPROTO) exists only after the fix."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-30T12:31:52.756Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0","versionEndExcluding":"5.10.273"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0","versionEndExcluding":"5.15.221"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0","versionEndExcluding":"6.1.188"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0","versionEndExcluding":"6.6.157"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0","versionEndExcluding":"6.12.109"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0","versionEndExcluding":"6.18.50"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0","versionEndExcluding":"7.2.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-89480","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2026-10-16T19:22:32.814624Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-16T19:26:39.543Z"}}]}}}