[PATCH 6.1.y] nvme: make the DH-HMAC-CHAP secret attributes readable by root only

[Sasha Levin <sashal@kernel.org>]

From: Martin Belanger <martin.nvme.dev@gmail.com>

[ Upstream commit bbca7c312ab25efd0024eb87545c51a76ab2ea39 ]

The dhchap_secret and dhchap_ctrl_secret sysfs attributes have mode
0644. Their show functions return the secret, so any local user can
read the DH-HMAC-CHAP secrets of a connected controller.

Define them with DEVICE_ATTR_ADMIN_RW(), which sets mode 0600. The
macro takes the show and store functions from the attribute name, so
rename them. Writing the attributes was already limited to root and is
not changed.

Fixes: f50fff73d620 ("nvme: implement In-Band authentication")
Cc: stable@vger.kernel.org
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Assisted-by: LLM
Signed-off-by: Martin Belanger <martin.nvme.dev@gmail.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
[ sashal: Applied the changes to the NVMe core code because the sysfs attributes have not been moved to a separate file. ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/nvme/host/core.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 26233e6a50da9..9521126738940 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -3847,7 +3847,7 @@ static ssize_t dctype_show(struct device *dev,
 static DEVICE_ATTR_RO(dctype);
 
 #ifdef CONFIG_NVME_AUTH
-static ssize_t nvme_ctrl_dhchap_secret_show(struct device *dev,
+static ssize_t dhchap_secret_show(struct device *dev,
 		struct device_attribute *attr, char *buf)
 {
 	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
@@ -3858,7 +3858,7 @@ static ssize_t nvme_ctrl_dhchap_secret_show(struct device *dev,
 	return sysfs_emit(buf, "%s\n", opts->dhchap_secret);
 }
 
-static ssize_t nvme_ctrl_dhchap_secret_store(struct device *dev,
+static ssize_t dhchap_secret_store(struct device *dev,
 		struct device_attribute *attr, const char *buf, size_t count)
 {
 	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
@@ -3899,10 +3899,9 @@ static ssize_t nvme_ctrl_dhchap_secret_store(struct device *dev,
 
 	return count;
 }
-static DEVICE_ATTR(dhchap_secret, S_IRUGO | S_IWUSR,
-	nvme_ctrl_dhchap_secret_show, nvme_ctrl_dhchap_secret_store);
+static DEVICE_ATTR_ADMIN_RW(dhchap_secret);
 
-static ssize_t nvme_ctrl_dhchap_ctrl_secret_show(struct device *dev,
+static ssize_t dhchap_ctrl_secret_show(struct device *dev,
 		struct device_attribute *attr, char *buf)
 {
 	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
@@ -3913,7 +3912,7 @@ static ssize_t nvme_ctrl_dhchap_ctrl_secret_show(struct device *dev,
 	return sysfs_emit(buf, "%s\n", opts->dhchap_ctrl_secret);
 }
 
-static ssize_t nvme_ctrl_dhchap_ctrl_secret_store(struct device *dev,
+static ssize_t dhchap_ctrl_secret_store(struct device *dev,
 		struct device_attribute *attr, const char *buf, size_t count)
 {
 	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
@@ -3954,8 +3953,7 @@ static ssize_t nvme_ctrl_dhchap_ctrl_secret_store(struct device *dev,
 
 	return count;
 }
-static DEVICE_ATTR(dhchap_ctrl_secret, S_IRUGO | S_IWUSR,
-	nvme_ctrl_dhchap_ctrl_secret_show, nvme_ctrl_dhchap_ctrl_secret_store);
+static DEVICE_ATTR_ADMIN_RW(dhchap_ctrl_secret);
 #endif
 
 static struct attribute *nvme_dev_attrs[] = {
-- 
2.53.0