[PATCH v2] ASoC: mediatek: mt8365: Add check for devm_kcalloc() in mt8365_afe_suspend()

[Guangshuo Li <lgs201920130244@gmail.com>]

devm_kcalloc() may fail. mt8365_afe_suspend() uses afe->reg_back_up
unconditionally after allocation and writes afe->reg_back_up[i], which
can lead to a NULL pointer dereference under low-memory conditions.

Add a NULL check and bail out with -ENOMEM, making sure to disable the
main clock via the existing error path to keep clock state balanced.

Fixes: e1991d102bc2 ("ASoC: mediatek: mt8365: Add the AFE driver support")
Cc: stable@vger.kernel.org
---
changelog:
v2:
- Return -ENOMEM directly on allocation failure without goto/label.
- Disable the main clock before returning to keep clock state balanced.

Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
---
 sound/soc/mediatek/mt8365/mt8365-afe-pcm.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/sound/soc/mediatek/mt8365/mt8365-afe-pcm.c b/sound/soc/mediatek/mt8365/mt8365-afe-pcm.c
index 10793bbe9275..55d832e05072 100644
--- a/sound/soc/mediatek/mt8365/mt8365-afe-pcm.c
+++ b/sound/soc/mediatek/mt8365/mt8365-afe-pcm.c
@@ -1975,11 +1975,15 @@ static int mt8365_afe_suspend(struct device *dev)
 
 	mt8365_afe_enable_main_clk(afe);
 
-	if (!afe->reg_back_up)
+	if (!afe->reg_back_up) {
 		afe->reg_back_up =
 			devm_kcalloc(dev, afe->reg_back_up_list_num,
-				     sizeof(unsigned int), GFP_KERNEL);
-
+				    sizeof(unsigned int), GFP_KERNEL);
+		if (!afe->reg_back_up) {
+			mt8365_afe_disable_main_clk(afe);
+			return -ENOMEM;
+		}
+	}
 	for (i = 0; i < afe->reg_back_up_list_num; i++)
 		regmap_read(regmap, afe->reg_back_up_list[i],
 			    &afe->reg_back_up[i]);
-- 
2.43.0