RE: [PATCH v1] mmc-utils: Fix for Firmware Version string printing

From: Avri Altman
Date: Tue Jul 13 2021 - 04:00:29 EST


>
> From: Kimito Sakata <kimito.sakata@xxxxxxxxxx>
>
> Added a local buffer to create a NULL terminated string to print the
> Firmware Version instead of attempting to print directly from
> ext_csd buffer. The last byte of the Firmware Version field may not
> be NULL and the next field may also not be which may cause it to
> print garbage.
>
> Tested on x86 platform.
Fixes: 89cd01ed865a (mmc_utils: add ffu support)

Signed-off-by: Kimito Sakata <kimito.sakata@xxxxxxxxxx>
Reviewed-by: Avri Altman <avri.altman@xxxxxxx>

> ---
> mmc_cmds.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/mmc_cmds.c b/mmc_cmds.c
> index afa85b7..205e6e5 100644
> --- a/mmc_cmds.c
> +++ b/mmc_cmds.c
> @@ -1392,6 +1392,7 @@ int do_read_extcsd(int nargs, char **argv)
> __u32 regl;
> int fd, ret;
> char *device;
> + char lbuf[10];
> const char *str;
>
> if (nargs != 2) {
> @@ -1833,8 +1834,9 @@ int do_read_extcsd(int nargs, char **argv)
> }
>
> if (ext_csd_rev >= 7) {
> - printf("eMMC Firmware Version: %s\n",
> - (char*)&ext_csd[EXT_CSD_FIRMWARE_VERSION]);
> + memset(lbuf, 0, sizeof(lbuf));
> + strncpy(lbuf, (char*)&ext_csd[EXT_CSD_FIRMWARE_VERSION], 8);
> + printf("eMMC Firmware Version: %s\n", lbuf);
> printf("eMMC Life Time Estimation A
> [EXT_CSD_DEVICE_LIFE_TIME_EST_TYP_A]: 0x%02x\n",
> ext_csd[EXT_CSD_DEVICE_LIFE_TIME_EST_TYP_A]);
> printf("eMMC Life Time Estimation B
> [EXT_CSD_DEVICE_LIFE_TIME_EST_TYP_B]: 0x%02x\n",
> --
> 2.31.1