[PATCH 1/2] board: dhelectronics: Check pointer before access in dh_get_value_from_eeprom_buffer()

[Marek Vasut]

The eip pointer in dh_get_value_from_eeprom_buffer() might be NULL.
The current NULL pointer check happens too late, after the eip was
accessed in variable assignment. Reorder the two, so the NULL pointer
check happens first, and any access second, otherwise the access may
trigger a hang or other undefined behavior.

Signed-off-by: Marek Vasut <marek.vasut at mailbox.org>
---
Cc: Christoph Niedermaier <cniedermaier at dh-electronics.com>
Cc: Simon Glass <sjg at chromium.org>
Cc: Tom Rini <trini at konsulko.com>
---
 board/dhelectronics/common/dh_common.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/board/dhelectronics/common/dh_common.c b/board/dhelectronics/common/dh_common.c
index 9f8e5754d8c..aeabd617374 100644
--- a/board/dhelectronics/common/dh_common.c
+++ b/board/dhelectronics/common/dh_common.c
@@ -131,14 +131,17 @@ int dh_read_eeprom_id_page(u8 *eeprom_buffer, const char *alias)
 int dh_get_value_from_eeprom_buffer(enum eip_request_values request, u8 *data, int data_len,
 				    struct eeprom_id_page *eip)
 {
-	const char fin_chr = (eip->pl.item_prefix & DH_ITEM_PREFIX_FIN_BIT) ?
-			     DH_ITEM_PREFIX_FIN_FLASHED_CHR : DH_ITEM_PREFIX_FIN_HALF_CHR;
-	const u8 soc_coded = eip->pl.item_prefix & 0xf;
+	char fin_chr;
+	u8 soc_coded;
 	char soc_chr;
 
 	if (!eip)
 		return -EINVAL;
 
+	fin_chr = (eip->pl.item_prefix & DH_ITEM_PREFIX_FIN_BIT) ?
+		  DH_ITEM_PREFIX_FIN_FLASHED_CHR : DH_ITEM_PREFIX_FIN_HALF_CHR;
+	soc_coded = eip->pl.item_prefix & 0xf;
+
 	/* Copy requested data */
 	switch (request) {
 	case DH_MAC0:
-- 
2.50.1