{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-89973", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.779Z", "datePublished": "2026-09-16T10:32:52.409Z", "dateUpdated": "2026-10-19T08:55:48.143Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:55:48.143Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnvme-tcp: check the data direction of a C2HData PDU\n\nnvme_tcp_handle_c2h_data() finds the request by command id and checks\nthat it has a payload, but it does not check that the command asked for\ndata to be read. A controller that answers a write command with C2HData\ntherefore reaches nvme_tcp_recv_data(), where _copy_to_iter() hits\nWARN_ON_ONCE(i->data_source) and returns 0. The receive path turns that\ninto -EFAULT and resets the controller.\n\nNo data is copied, so this is not memory corruption. What a controller\ngets is a kernel warning it can raise at will, which is fatal on a host\nbooted with panic_on_warn.\n\nThe send path already knows the direction - it consults rq_data_dir()\nwhen it builds a command - and nvme_tcp_handle_r2t() checks the length\nand the offset of the request it names. The C2HData path does not check\nthe direction at all.\n\nReject a C2HData PDU whose command is not a read. Rejecting it fails\nthe command and resets the controller, as the neighbouring check in this\nfunction does; what goes away is the warning.\n\n [ 6.885580] ------------[ cut here ]------------\n [ 6.886457] WARNING: lib/iov_iter.c:193 at _copy_to_iter+0x289/0x1330, CPU#0: kworker/0:1H/71\n [ 6.888137] CPU: 0 UID: 0 PID: 71 Comm: kworker/0:1H Not tainted 7.2.0-rc5-NVMETCP-gf5098b6bae76 #1 PREEMPT(lazy)\n [ 6.891165] Workqueue: nvme_tcp_wq nvme_tcp_io_work\n [ 6.891875] RIP: 0010:_copy_to_iter+0x289/0x1330\n [ 6.903739] Call Trace:\n [ 6.904085] \n [ 6.909254] __skb_datagram_iter+0x433/0x820\n [ 6.911026] skb_copy_datagram_iter+0x37/0x120\n [ 6.911622] nvme_tcp_recv_skb+0xa07/0x4320\n [ 6.913378] __tcp_read_sock+0x1ab/0x810\n [ 6.915788] nvme_tcp_try_recv+0x152/0x1e0\n [ 6.918222] nvme_tcp_io_work+0x1e4/0x6c0\n [ 6.926906] \n [ 6.927226] ---[ end trace 0000000000000000 ]---\n [ 6.927878] nvme nvme0: queue 1 failed to copy request 0x71 data\n [ 6.928709] nvme nvme0: receive failed: -14" } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H", "baseScore": 8.2, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:N - The nvme-tcp host receive path (nvme_tcp_data_ready -> nvme_tcp_try_recv -> nvme_tcp_recv_skb -> nvme_tcp_handle_c2h_data) parses C2HData PDUs from a remote NVMe/TCP target over routable TCP (typically port 4420); a malicious or compromised target, or an on-path injector into the default-unencrypted stream, triggers the bug from the network.\nAC:L - A malicious controller that replies to any in-flight write-direction command with a well-formed C2HData PDU always hits WARN_ON_ONCE(i->data_source) in _copy_to_iter; writes occur from writeback, discards, and init-time Set Features. No race, special memory layout, or rare config beyond CONFIG_NVME_TCP is required.\nPR:N - NVMe/TCP authentication (TLS and DH-HMAC-CHAP) is optional and off by default, so the connected fabric peer needs no credentials or privileges on the victim host; it simply answers I/O the host is already sending.\nUI:N - No victim action is required at exploit time; once the host is connected (including nvmf-autoconnect at boot), ordinary writeback, journal I/O, and controller-init Set Features with a data buffer issue write-direction commands that the malicious target answers with C2HData.\nS:U - The WARN splat, NVMe controller reset, and any panic_on_warn crash remain inside the host kernel. This is not a VM escape, IOMMU bypass, or sandbox boundary crossing.\nC:L - WARN_ON_ONCE in _copy_to_iter calls __warn()/dump_stack(), disclosing kernel text addresses in dmesg. No data is copied (the write iterator is ITER_SOURCE and copy_to_iter returns 0), so there is no use-after-free or arbitrary kernel read.\nI:N - The receive path turns the failed copy into -EFAULT and resets the controller; _copy_to_iter returns 0 without writing, so there is no memory corruption, write primitive, or control-flow hijack.\nA:H - The reporter reproduced WARNING in _copy_to_iter from nvme_tcp_io_work, which panics hosts with panic_on_warn or warn_limit. Independently, every C2HData-for-write returns -EFAULT and runs nvme_tcp_error_recovery(), so a malicious target can repeatedly take down NVMe-oF storage." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/nvme/host/tcp.c" ], "versions": [ { "version": "3f2304f8c6d6ed97849057bd16fee99e434ca796", "lessThan": "df74950ba6008655d4a977d17df7faf4b6e52b74", "status": "affected", "versionType": "git" }, { "version": "3f2304f8c6d6ed97849057bd16fee99e434ca796", "lessThan": "980d990f3c0560d7dfbfbf14699651fdf02f26ee", "status": "affected", "versionType": "git" }, { "version": "3f2304f8c6d6ed97849057bd16fee99e434ca796", "lessThan": "5b115d932f6e769ac80783fb18edd21b0aed256e", "status": "affected", "versionType": "git" }, { "version": "3f2304f8c6d6ed97849057bd16fee99e434ca796", "lessThan": "0673a2affe45ca76b60de31a83c67b1e60f81bde", "status": "affected", "versionType": "git" }, { "version": "3f2304f8c6d6ed97849057bd16fee99e434ca796", "lessThan": "80d56202fbdff8906be6954b2776e5c14a4026f2", "status": "affected", "versionType": "git" }, { "version": "3f2304f8c6d6ed97849057bd16fee99e434ca796", "lessThan": "b4af7999a998787d5eb6facb5a333e04a4f1d2d9", "status": "affected", "versionType": "git" }, { "version": "3f2304f8c6d6ed97849057bd16fee99e434ca796", "lessThan": "a0c389b8a495bda1eb719d2503853c924b7a8355", "status": "affected", "versionType": "git" }, { "version": "3f2304f8c6d6ed97849057bd16fee99e434ca796", "lessThan": "f83af377c148f6ad94b41c0e8313f12adf45e1c1", "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/nvme/host/tcp.c" ], "versions": [ { "version": "5.0", "status": "affected" }, { "version": "0", "lessThan": "5.0", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.270", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.221", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.188", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.157", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.110", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.51", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.5", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "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": "5.0", "versionEndExcluding": "5.10.270" }, { "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": "6.12.110" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.0", "versionEndExcluding": "6.18.51" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.0", "versionEndExcluding": "7.2.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.0", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/df74950ba6008655d4a977d17df7faf4b6e52b74" }, { "url": "https://git.kernel.org/stable/c/980d990f3c0560d7dfbfbf14699651fdf02f26ee" }, { "url": "https://git.kernel.org/stable/c/5b115d932f6e769ac80783fb18edd21b0aed256e" }, { "url": "https://git.kernel.org/stable/c/0673a2affe45ca76b60de31a83c67b1e60f81bde" }, { "url": "https://git.kernel.org/stable/c/80d56202fbdff8906be6954b2776e5c14a4026f2" }, { "url": "https://git.kernel.org/stable/c/b4af7999a998787d5eb6facb5a333e04a4f1d2d9" }, { "url": "https://git.kernel.org/stable/c/a0c389b8a495bda1eb719d2503853c924b7a8355" }, { "url": "https://git.kernel.org/stable/c/f83af377c148f6ad94b41c0e8313f12adf45e1c1" } ], "title": "nvme-tcp: check the data direction of a C2HData PDU", "x_generator": { "engine": "bippy-1.2.0" } } } }