[PATCH 5/9] tcmu: check if dev is configured before block/reset

[Mike Christie <mchristi@redhat.com>]

Do not allow userspace to block or reset the ring until the device has
been configured. This will prevent the bug where userspace can write to
those files and access mb_addr before it has been setup.

Signed-off-by: Mike Christie <mchristi@redhat.com>
---
 drivers/target/target_core_user.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c
index bc8121f..d6b4022 100644
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c
@@ -2480,6 +2480,11 @@ static ssize_t tcmu_block_dev_store(struct config_item *item, const char *page,
 	u8 val;
 	int ret;
 
+	if (!target_dev_configured(&udev->se_dev)) {
+		pr_err("Device is not configured.\n");
+		return -EINVAL;
+	}
+
 	ret = kstrtou8(page, 0, &val);
 	if (ret < 0)
 		return ret;
@@ -2507,6 +2512,11 @@ static ssize_t tcmu_reset_ring_store(struct config_item *item, const char *page,
 	u8 val;
 	int ret;
 
+	if (!target_dev_configured(&udev->se_dev)) {
+		pr_err("Device is not configured.\n");
+		return -EINVAL;
+	}
+
 	ret = kstrtou8(page, 0, &val);
 	if (ret < 0)
 		return ret;
-- 
1.8.3.1