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

[Christoph Niedermaier <cniedermaier@dh-electronics.com>]

From: Marek Vasut <marek.vasut@mailbox.org>
Sent: Sunday, September 7, 2025 3:01 AM
> 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@mailbox.org>
> ---
> Cc: Christoph Niedermaier <cniedermaier@dh-electronics.com>
> Cc: Simon Glass <sjg@chromium.org>
> Cc: Tom Rini <trini@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:

Reviewed-by: Christoph Niedermaier <cniedermaier@dh-electronics.com>