From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D2D7D3932DA; Sat, 12 Sep 2026 18:27:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789237680; cv=none; b=ohI/O77tuAMVQsnOMnJ/azr/gnT0f5RYNDoYccGPgUZOKQojMWfa0jjwodMyvTXuy46QNGrF/FAekTXkn7e683yMHpzk7fsqO8Ho00e0UtPihBJxY1HqS/mADljWaob9sGnDw1Io6gbL5i/vqiiQz8mUmfkz3RRMueDYAYeXVww= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789237680; c=relaxed/simple; bh=yHUz+lffLENVb6lsoMAPZblcaP5T2x54/LcYtgni5yQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=huUAYfG1RSLvw7sydriMKZli+xpDwKlx1srlyd2AyUWCqSx/Xmxwwy/Tb/av3iVxXIroIkWe6cYJc1bJm1R8QoW0SVeAVT/HNI7nRbbzhfMpWKfaQx34ExGxkr0AIC9A+/y/aHhKn5leyKjSzY5vr4cm2mXiWcl8W0qcToGV4/E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=S+4SSJQs; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="S+4SSJQs" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D3E4B1F000FF; Sat, 12 Sep 2026 18:27:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789237678; bh=x8CB1swAQwP6NTzrfqpsMl/RSJ0RLfhHIsmpVsIHnkU=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=S+4SSJQsD/xanWTeeDmS6AZEUWhVzFiCIkHk5u8q70PhSzq4jXK/Wat4njWZuEAb4 qDDJOSCd29CshCcQVLlWLtAbDnqKs+isO3X6AumzXs/CFPnNA4j+5OKFZnuIT7stAZ tlS1CTW3r2c3/mvmbtlpcJaZs+7QBe7kYWfZhhwg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Christoph Hellwig , Yehyeong Lee , Keith Busch Subject: [PATCH 5.15 264/935] nvme-tcp: check the data direction of a C2HData PDU Date: Sat, 12 Sep 2026 08:54:54 +0200 Message-ID: <20260912065532.880444846@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065526.833703348@linuxfoundation.org> References: <20260912065526.833703348@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Yehyeong Lee 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] [ 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] [ 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 Signed-off-by: Yehyeong Lee Signed-off-by: Keith Busch Signed-off-by: Greg Kroah-Hartman --- drivers/nvme/host/tcp.c | 7 +++++++ 1 file changed, 7 insertions(+) --- a/drivers/nvme/host/tcp.c +++ b/drivers/nvme/host/tcp.c @@ -592,6 +592,13 @@ static int nvme_tcp_handle_c2h_data(stru 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; + } + req = blk_mq_rq_to_pdu(rq); if (!blk_rq_payload_bytes(rq) || !req->curr_bio || !req->data_len) { dev_err(queue->ctrl->ctrl.device,