[PATCH v2] staging: rtl8723bs: Add error handling for sd_read().

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

The sdio_read32() calls sd_read(), but does not handle the error if
sd_read() fails. This could lead to subsequent operations processing
invalid data. A proper implementation can be found in sdio_readN().

Add error handling to the sd_read(), ensuring that the memcpy() is
only performed when the read operation is successful.

Fixes: 554c0a3abf21 ("staging: Add rtl8723bs sdio wifi driver")
Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>
---
 drivers/staging/rtl8723bs/hal/sdio_ops.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/rtl8723bs/hal/sdio_ops.c b/drivers/staging/rtl8723bs/hal/sdio_ops.c
index 21e9f1858745..b21fd087c9a0 100644
--- a/drivers/staging/rtl8723bs/hal/sdio_ops.c
+++ b/drivers/staging/rtl8723bs/hal/sdio_ops.c
@@ -185,9 +185,11 @@ static u32 sdio_read32(struct intf_hdl *intfhdl, u32 addr)
 			return SDIO_ERR_VAL32;
 
 		ftaddr &= ~(u16)0x3;
-		sd_read(intfhdl, ftaddr, 8, tmpbuf);
-		memcpy(&le_tmp, tmpbuf + shift, 4);
-		val = le32_to_cpu(le_tmp);
+		val = sd_read(intfhdl, ftaddr, 8, tmpbuf);
+		if (!val) {
+			memcpy(&le_tmp, tmpbuf + shift, 4);
+			val = le32_to_cpu(le_tmp);
+		}
 
 		kfree(tmpbuf);
 	}
-- 
2.42.0.windows.2