From: Yehyeong Lee <yhlee@isslab.korea.ac.kr> stable inclusion from stable-v6.6.157 commit 0673a2affe45ca76b60de31a83c67b1e60f81bde category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/19102 CVE: CVE-2026-89973 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... ------------------------------ commit f83af377c148f6ad94b41c0e8313f12adf45e1c1 upstream. nvme_tcp_handle_c2h_data() finds the request by command id and checks that it has a payload, but it does not check that the command asked for data to be read. A controller that answers a write command with C2HData therefore reaches nvme_tcp_recv_data(), where _copy_to_iter() hits WARN_ON_ONCE(i->data_source) and returns 0. The receive path turns that into -EFAULT and resets the controller. No data is copied, so this is not memory corruption. What a controller gets is a kernel warning it can raise at will, which is fatal on a host booted with panic_on_warn. The send path already knows the direction - it consults rq_data_dir() when it builds a command - and nvme_tcp_handle_r2t() checks the length and the offset of the request it names. The C2HData path does not check the direction at all. Reject a C2HData PDU whose command is not a read. Rejecting it fails the command and resets the controller, as the neighbouring check in this function does; what goes away is the warning. [ 6.885580] ------------[ cut here ]------------ [ 6.886457] WARNING: lib/iov_iter.c:193 at _copy_to_iter+0x289/0x1330, CPU#0: kworker/0:1H/71 [ 6.888137] CPU: 0 UID: 0 PID: 71 Comm: kworker/0:1H Not tainted 7.2.0-rc5-NVMETCP-gf5098b6bae76 #1 PREEMPT(lazy) [ 6.891165] Workqueue: nvme_tcp_wq nvme_tcp_io_work [ 6.891875] RIP: 0010:_copy_to_iter+0x289/0x1330 [ 6.903739] Call Trace: [ 6.904085] <TASK> [ 6.909254] __skb_datagram_iter+0x433/0x820 [ 6.911026] skb_copy_datagram_iter+0x37/0x120 [ 6.911622] nvme_tcp_recv_skb+0xa07/0x4320 [ 6.913378] __tcp_read_sock+0x1ab/0x810 [ 6.915788] nvme_tcp_try_recv+0x152/0x1e0 [ 6.918222] nvme_tcp_io_work+0x1e4/0x6c0 [ 6.926906] </TASK> [ 6.927226] ---[ end trace 0000000000000000 ]--- [ 6.927878] nvme nvme0: queue 1 failed to copy request 0x71 data [ 6.928709] nvme nvme0: receive failed: -14 Fixes: 3f2304f8c6d6 ("nvme-tcp: add NVMe over TCP host driver") Cc: stable@vger.kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Yehyeong Lee <yhlee@isslab.korea.ac.kr> Signed-off-by: Keith Busch <kbusch@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Conflicts: drivers/nvme/host/tcp.c [Upstream commit 3a4aa9e6ad3e ("nvme-tcp: do not accept C2HData based on blk_rq_payload_bytes() alone") is not backported, so the payload check in nvme_tcp_handle_c2h_data() is still the plain blk_rq_payload_bytes() form; insert the rq_data_dir() check after the request lookup, before it.] Signed-off-by: Chen Yuxi <chenyuxi19@huawei.com> --- drivers/nvme/host/tcp.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c index 691338bf63ab..cd89be821763 100644 --- a/drivers/nvme/host/tcp.c +++ b/drivers/nvme/host/tcp.c @@ -597,6 +597,13 @@ static int nvme_tcp_handle_c2h_data(struct nvme_tcp_queue *queue, return -ENOENT; } + if (rq_data_dir(rq) != READ) { + dev_err(queue->ctrl->ctrl.device, + "queue %d tag %#x unexpected data for a write\n", + nvme_tcp_queue_id(queue), rq->tag); + return -EIO; + } + if (!blk_rq_payload_bytes(rq)) { dev_err(queue->ctrl->ctrl.device, "queue %d tag %#x unexpected data\n", -- 2.34.1