[PATCH v2] wifi: wilc1000: Add error handling for wilc_sdio_cmd52()

[Wentao Liang <vulab@iscas.ac.cn>]

The wilc_sdio_read_size() calls wilc_sdio_cmd52() but does not check the
return value. This could lead to execution with potentially invalid data
if wilc_sdio_cmd52() fails. A proper implementation can be found in
wilc_sdio_read_reg().

Add error handling for wilc_sdio_cmd52(). If wilc_sdio_cmd52() fails,
log an error message via dev_err().

Fixes: 0e1af73ddeb9 ("staging/wilc1000: use proper naming for global symbols")
Cc: stable@vger.kernel.org # v4.15
Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>
---
v2: Fix code error.

 drivers/net/wireless/microchip/wilc1000/sdio.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/microchip/wilc1000/sdio.c b/drivers/net/wireless/microchip/wilc1000/sdio.c
index 5262c8846c13..8ff49b08bbd2 100644
--- a/drivers/net/wireless/microchip/wilc1000/sdio.c
+++ b/drivers/net/wireless/microchip/wilc1000/sdio.c
@@ -771,6 +771,7 @@ static int wilc_sdio_read_size(struct wilc *wilc, u32 *size)
 {
 	u32 tmp;
 	struct sdio_cmd52 cmd;
+	struct sdio_func *func = dev_to_sdio_func(wilc->dev);
 
 	/**
 	 *      Read DMA count in words
@@ -780,12 +781,20 @@ static int wilc_sdio_read_size(struct wilc *wilc, u32 *size)
 	cmd.raw = 0;
 	cmd.address = WILC_SDIO_INTERRUPT_DATA_SZ_REG;
 	cmd.data = 0;
-	wilc_sdio_cmd52(wilc, &cmd);
+	ret = wilc_sdio_cmd52(wilc, &cmd);
+	if (ret) {
+		dev_err(&func->dev, "Fail cmd 52, interrupt data register...\n");
+		return ret;
+	}
 	tmp = cmd.data;
 
 	cmd.address = WILC_SDIO_INTERRUPT_DATA_SZ_REG + 1;
 	cmd.data = 0;
-	wilc_sdio_cmd52(wilc, &cmd);
+	ret = wilc_sdio_cmd52(wilc, &cmd);
+	if (ret) {
+		dev_err(&func->dev, "Fail cmd 52, interrupt data register...\n");
+		return ret;
+	}
 	tmp |= (cmd.data << 8);
 
 	*size = tmp;
-- 
2.42.0.windows.2