[PATCH] input: avoid NULL dereference

[Heinrich Schuchardt]

Before using the result of env_get("stdin") we must check if it is NULL.

Use attribute __maybe unused instead of dummy assignment.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt at canonical.com>
---
 drivers/input/input.c | 21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/drivers/input/input.c b/drivers/input/input.c
index a4341e8c7c..2330b21f71 100644
--- a/drivers/input/input.c
+++ b/drivers/input/input.c
@@ -666,19 +666,22 @@ int input_init(struct input_config *config, int leds)
 
 int input_stdio_register(struct stdio_dev *dev)
 {
-	int error;
+	__maybe_unused int error;
 
 	error = stdio_register(dev);
 #if !defined(CONFIG_SPL_BUILD) || CONFIG_IS_ENABLED(ENV_SUPPORT)
-	/* check if this is the standard input device */
-	if (!error && strcmp(env_get("stdin"), dev->name) == 0) {
-		/* reassign the console */
-		if (OVERWRITE_CONSOLE ||
-				console_assign(stdin, dev->name))
-			return -1;
+	if (!error) {
+		const char *cstdin;
+
+		/* check if this is the standard input device */
+		cstdin = env_get("stdin");
+		if (cstdin && !strcmp(cstdin, dev->name)) {
+			/* reassign the console */
+			if (OVERWRITE_CONSOLE ||
+			    console_assign(stdin, dev->name))
+				return -1;
+		}
 	}
-#else
-	error = error;
 #endif
 
 	return 0;
-- 
2.40.1