Re: [PATCH v3 1/2] mwifiex: Use a define for firmware version string length

[Jonas Dreßler]

On 11/3/21 18:28, Brian Norris wrote:
> On Wed, Nov 03, 2021 at 06:10:54PM +0100, Jonas Dreßler wrote:
> > Since the version string we get from the firmware is always 128
> > characters long, use a define for this size instead of having the number
> > 128 copied all over the place.
> >
> > Signed-off-by: Jonas Dreßler <verdre@xxxxxxx>
>
> Thanks for this patch. For the series:
>
> Reviewed-by: Brian Norris <briannorris@xxxxxxxxxxxx>
>
> > ---
> >   drivers/net/wireless/marvell/mwifiex/fw.h          | 4 +++-
> >   drivers/net/wireless/marvell/mwifiex/main.h        | 2 +-
> >   drivers/net/wireless/marvell/mwifiex/sta_cmdresp.c | 5 +++--
> >   3 files changed, 7 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/net/wireless/marvell/mwifiex/fw.h b/drivers/net/wireless/marvell/mwifiex/fw.h
> > index 2ff23ab259ab..63c25c69ed2b 100644
> > --- a/drivers/net/wireless/marvell/mwifiex/fw.h
> > +++ b/drivers/net/wireless/marvell/mwifiex/fw.h
> > @@ -2071,9 +2071,11 @@ struct mwifiex_ie_types_robust_coex {
> >   	__le32 mode;
> >   } __packed;
> >   
> > +#define MWIFIEX_VERSION_STR_LENGTH  128
> > +
> >   struct host_cmd_ds_version_ext {
> >   	u8 version_str_sel;
> > -	char version_str[128];
> > +	char version_str[MWIFIEX_VERSION_STR_LENGTH];
> >   } __packed;
> >   
> >   struct host_cmd_ds_mgmt_frame_reg {
> > diff --git a/drivers/net/wireless/marvell/mwifiex/main.h b/drivers/net/wireless/marvell/mwifiex/main.h
> > index 90012cbcfd15..65609ea2327e 100644
> > --- a/drivers/net/wireless/marvell/mwifiex/main.h
> > +++ b/drivers/net/wireless/marvell/mwifiex/main.h
> > @@ -646,7 +646,7 @@ struct mwifiex_private {
> >   	struct wireless_dev wdev;
> >   	struct mwifiex_chan_freq_power cfp;
> >   	u32 versionstrsel;
> > -	char version_str[128];
> > +	char version_str[MWIFIEX_VERSION_STR_LENGTH];
> >   #ifdef CONFIG_DEBUG_FS
> >   	struct dentry *dfs_dev_dir;
> >   #endif
> > diff --git a/drivers/net/wireless/marvell/mwifiex/sta_cmdresp.c b/drivers/net/wireless/marvell/mwifiex/sta_cmdresp.c
> > index 6b5d35d9e69f..20b69a37f9e1 100644
> > --- a/drivers/net/wireless/marvell/mwifiex/sta_cmdresp.c
> > +++ b/drivers/net/wireless/marvell/mwifiex/sta_cmdresp.c
> > @@ -711,8 +711,9 @@ static int mwifiex_ret_ver_ext(struct mwifiex_private *priv,
> >   	if (version_ext) {
> >   		version_ext->version_str_sel = ver_ext->version_str_sel;
> >   		memcpy(version_ext->version_str, ver_ext->version_str,
> > -		       sizeof(char) * 128);
> > -		memcpy(priv->version_str, ver_ext->version_str, 128);
> > +		       MWIFIEX_VERSION_STR_LENGTH);
> > +		memcpy(priv->version_str, ver_ext->version_str,
> > +		       MWIFIEX_VERSION_STR_LENGTH);
>
> Not related to your patch, but this highlights that nobody is ensuring
> this string is 0-terminated, and various other places (notably, *not*
> your patch 2!) assume that it is.
>
> We should either fix those to use an snprintf()/length-restricted
> variant, or else just force:
>
> 		priv->version_str[MWIFIEX_VERSION_STR_LENGTH - 1] = '\0';
>
> here.

Indeed, right now we just trust the firmware to make sure that's the case.

Let me add another patch appending the '\0' to priv->version_str...

> But that's a separate issue/patch. I can cook one on top of your series
> when it gets merged if you don't want to.
>
> Brian
>
> >   	}
> >   	return 0;
> >   }
> > --
> > 2.33.1