[PATCH 2/2] mtd: rawnand: arasan: fix GPIO CS leak on probe error paths

[Zhao Feng]

The CS GPIO descriptors acquired by anfc_parse_cs() via
rawnand_dt_parse_gpio_cs() are only released in anfc_remove().  Two
probe error paths leak them:

- anfc_parse_cs() itself returns -EINVAL on an invalid DT GPIO CS
  layout without releasing the freshly acquired descriptors;
- anfc_probe() bails out when anfc_chips_init() fails, leaving the
  successfully parsed CS array behind.

Factor the gpiod_put() loop of anfc_remove() into anfc_put_cs() and
call it from both error paths as well.  gpiod_put() accepts NULL, so
this is also safe when the default all-NULL CS array is in place.

Fixes: acbd3d0945f9 ("mtd: rawnand: arasan: Leverage additional GPIO CS")
Cc: stable at vger.kernel.org
Signed-off-by: Zhao Feng <zhaofeng2 at cmss.chinamobile.com>
---
Verified against current upstream master.  Not runtime-tested (no
Arasan hardware).

 drivers/mtd/nand/raw/arasan-nand-controller.c | 26 ++++++++++++++----
 1 file changed, 18 insertions(+), 8 deletions(-)

diff --git a/drivers/mtd/nand/raw/arasan-nand-controller.c b/drivers/mtd/nand/raw/arasan-nand-controller.c
--- a/drivers/mtd/nand/raw/arasan-nand-controller.c
+++ b/drivers/mtd/nand/raw/arasan-nand-controller.c
@@ -1391,6 +1391,14 @@ static void anfc_reset(struct arasan_nfc *nfc)
 
 	nfc->cur_cs = -1;
 }
 
+static void anfc_put_cs(struct arasan_nfc *nfc)
+{
+	int i;
+
+	for (i = 0; i < nfc->ncs; i++)
+		gpiod_put(nfc->cs_array[i]);
+}
+
 static int anfc_parse_cs(struct arasan_nfc *nfc)
 {
@@ -1413,7 +1421,9 @@ static int anfc_parse_cs(struct arasan_nfc *nfc)
 		if (nfc->ncs > 2 && !nfc->cs_array[0] && !nfc->cs_array[1]) {
 			dev_err(nfc->dev,
 				"Assign a single native CS when using GPIOs\n");
+			anfc_put_cs(nfc);
+
 			return -EINVAL;
 		}
 
 		if (nfc->cs_array[0])
@@ -1469,23 +1479,23 @@ static int anfc_probe(struct platform_device *pdev)
 
 	ret = anfc_chips_init(nfc);
 	if (ret)
-		return ret;
+		goto err_put_cs;
 
 	platform_set_drvdata(pdev, nfc);
 
 	return 0;
+
+err_put_cs:
+	anfc_put_cs(nfc);
+
+	return ret;
 }
 
 static void anfc_remove(struct platform_device *pdev)
 {
-	int i;
 	struct arasan_nfc *nfc = platform_get_drvdata(pdev);
 
-	for (i = 0; i < nfc->ncs; i++) {
-		if (nfc->cs_array[i]) {
-			gpiod_put(nfc->cs_array[i]);
-		}
-	}
-
+	anfc_put_cs(nfc);
+
 	anfc_chips_cleanup(nfc);
 }
-- 
2.39.2