linux-kernel - [PATCH v3 8/8] nvme-tcp: Allow userspace to trigger a KeyUpdate with debugfs

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20251003043140.1341958-9-alistair.francis@wdc.com>
Date: Fri,  3 Oct 2025 14:31:39 +1000
From: alistair23@...il.com
To: chuck.lever@...cle.com,
	hare@...nel.org,
	kernel-tls-handshake@...ts.linux.dev,
	netdev@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	linux-doc@...r.kernel.org,
	linux-nvme@...ts.infradead.org,
	linux-nfs@...r.kernel.org
Cc: kbusch@...nel.org,
	axboe@...nel.dk,
	hch@....de,
	sagi@...mberg.me,
	kch@...dia.com,
	hare@...e.de,
	alistair23@...il.com,
	Alistair Francis <alistair.francis@....com>
Subject: [PATCH v3 8/8] nvme-tcp: Allow userspace to trigger a KeyUpdate with debugfs

From: Alistair Francis <alistair.francis@....com>

Allow userspace to trigger a KeyUpdate via debugfs. This patch exposes a
key_update file that can be written to with the queue number to trigger
a KeyUpdate on that queue.

Signed-off-by: Alistair Francis <alistair.francis@....com>
---
v3:
 - New patch

 drivers/nvme/host/tcp.c | 72 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 72 insertions(+)

diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
index 4f27319f0078..8c6d18727e90 100644
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -11,6 +11,7 @@
 #include <linux/crc32.h>
 #include <linux/nvme-tcp.h>
 #include <linux/nvme-keyring.h>
+#include <linux/debugfs.h>
 #include <net/sock.h>
 #include <net/tcp.h>
 #include <net/tls.h>
@@ -1432,6 +1433,75 @@ static void update_tls_keys(struct nvme_tcp_queue *queue)
 	}
 }
 
+#ifdef CONFIG_NVME_TCP_TLS
+#define NVME_DEBUGFS_RW_ATTR(field) \
+	static int field##_open(struct inode *inode, struct file *file) \
+	{ return single_open(file, field##_show, inode->i_private); } \
+	\
+	static const struct file_operations field##_fops = { \
+		.open = field##_open, \
+		.read = seq_read, \
+		.write = field##_write, \
+		.release = single_release, \
+	}
+
+static int nvme_ctrl_key_update_show(struct seq_file *m, void *p)
+{
+	seq_printf(m, "0\n");
+
+	return 0;
+}
+
+static ssize_t nvme_ctrl_key_update_write(struct file *file, const char __user *buf,
+					  size_t count, loff_t *ppos)
+{
+	struct seq_file *m = file->private_data;
+	struct nvme_ctrl *nctrl = m->private;
+	struct nvme_tcp_ctrl *ctrl = to_tcp_ctrl(nctrl);
+	char kbuf[16] = {0};
+	int queue_nr, rc;
+	struct nvme_tcp_queue *queue;
+
+	if (count > sizeof(kbuf) - 1)
+		return -EINVAL;
+	if (copy_from_user(kbuf, buf, count))
+		return -EFAULT;
+	kbuf[count] = 0;
+
+	rc = kstrtouint(kbuf, 10, &queue_nr);
+	if (rc)
+		return rc;
+
+	if (queue_nr >= nctrl->queue_count)
+		return -EINVAL;
+
+	queue = &ctrl->queues[queue_nr];
+
+	update_tls_keys(queue);
+
+	return count;
+}
+NVME_DEBUGFS_RW_ATTR(nvme_ctrl_key_update);
+#endif
+
+static void nvme_tcp_debugfs_init(struct nvme_ctrl *ctrl,
+			    const char *dev_name)
+{
+	struct dentry *parent;
+
+	/* create debugfs directory and attribute */
+	parent = debugfs_create_dir(dev_name, NULL);
+	if (IS_ERR(parent)) {
+		pr_warn("%s: failed to create debugfs directory\n", dev_name);
+		return;
+	}
+
+#ifdef CONFIG_NVME_TCP_TLS
+	debugfs_create_file("key_update", S_IWUSR, parent, ctrl,
+			    &nvme_ctrl_key_update_fops);
+#endif
+}
+
 static void nvme_tcp_io_work(struct work_struct *w)
 {
 	struct nvme_tcp_queue *queue =
@@ -3065,6 +3135,8 @@ static struct nvme_ctrl *nvme_tcp_create_ctrl(struct device *dev,
 	list_add_tail(&ctrl->list, &nvme_tcp_ctrl_list);
 	mutex_unlock(&nvme_tcp_ctrl_mutex);
 
+	nvme_tcp_debugfs_init(&ctrl->ctrl, dev_name(dev));
+
 	return &ctrl->ctrl;
 
 out_uninit_ctrl:
-- 
2.51.0