{"id":"CVE-2026-89973","published":"2026-09-16T11:17:08.057","lastModified":"2026-09-16T15:18:21.747","description":"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]  <TASK>\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]  </TASK>\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","cvssScore":8.2,"cvssSeverity":"HIGH","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H","cwes":[],"vendors":[],"products":[],"references":[{"url":"https://git.kernel.org/stable/c/0673a2affe45ca76b60de31a83c67b1e60f81bde","tags":[]},{"url":"https://git.kernel.org/stable/c/5b115d932f6e769ac80783fb18edd21b0aed256e","tags":[]},{"url":"https://git.kernel.org/stable/c/80d56202fbdff8906be6954b2776e5c14a4026f2","tags":[]},{"url":"https://git.kernel.org/stable/c/980d990f3c0560d7dfbfbf14699651fdf02f26ee","tags":[]},{"url":"https://git.kernel.org/stable/c/a0c389b8a495bda1eb719d2503853c924b7a8355","tags":[]},{"url":"https://git.kernel.org/stable/c/b4af7999a998787d5eb6facb5a333e04a4f1d2d9","tags":[]},{"url":"https://git.kernel.org/stable/c/df74950ba6008655d4a977d17df7faf4b6e52b74","tags":[]},{"url":"https://git.kernel.org/stable/c/f83af377c148f6ad94b41c0e8313f12adf45e1c1","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":null}