[PATCH] mailbox: imx-mailbox: fix scu msg header size check

[PATCH] mailbox: imx-mailbox: fix scu msg header size check

[peng.fan]

From: Peng Fan <peng.fan@nxp.com>

The i.MX8 SCU message header size is the number of "u32" elements,
not "u8", so fix the check.

Reported-by: coverity-bot <keescook+coverity-bot@chromium.org>
Addresses-Coverity-ID: 1461658 ("Memory - corruptions")
Signed-off-by: Peng Fan <peng.fan@nxp.com>
---

V2:
 I not include the fixes tag, since this patch still in next tree.

 drivers/mailbox/imx-mailbox.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/mailbox/imx-mailbox.c b/drivers/mailbox/imx-mailbox.c
index 7906624a731c..c2398cb63ea0 100644
--- a/drivers/mailbox/imx-mailbox.c
+++ b/drivers/mailbox/imx-mailbox.c
@@ -154,12 +154,12 @@ static int imx_mu_scu_tx(struct imx_mu_priv *priv,
 
 	switch (cp->type) {
 	case IMX_MU_TYPE_TX:
-		if (msg->hdr.size > sizeof(*msg)) {
+		if (msg->hdr.size > (sizeof(*msg) / 4)) {
 			/*
 			 * The real message size can be different to
 			 * struct imx_sc_rpc_msg_max size
 			 */
-			dev_err(priv->dev, "Exceed max msg size (%zu) on TX, got: %i\n", sizeof(*msg), msg->hdr.size);
+			dev_err(priv->dev, "Exceed max msg size (%zu) on TX, got: %i\n", sizeof(*msg) / 4, msg->hdr.size);
 			return -EINVAL;
 		}
 
@@ -198,9 +198,9 @@ static int imx_mu_scu_rx(struct imx_mu_priv *priv,
 	imx_mu_xcr_rmw(priv, 0, IMX_MU_xCR_RIEn(0));
 	*data++ = imx_mu_read(priv, priv->dcfg->xRR[0]);
 
-	if (msg.hdr.size > sizeof(msg)) {
+	if (msg.hdr.size > (sizeof(msg) / 4)) {
 		dev_err(priv->dev, "Exceed max msg size (%zu) on RX, got: %i\n",
-			sizeof(msg), msg.hdr.size);
+			sizeof(msg) / 4, msg.hdr.size);
 		return -EINVAL;
 	}
 
-- 
2.16.4

Re: [PATCH] mailbox: imx-mailbox: fix scu msg header size check

[Uwe Kleine-König]

On Tue, Apr 14, 2020 at 04:10:26PM +0800, peng.fan@nxp.com wrote:
> From: Peng Fan <peng.fan@nxp.com>
> 
> The i.MX8 SCU message header size is the number of "u32" elements,
> not "u8", so fix the check.
> 
> Reported-by: coverity-bot <keescook+coverity-bot@chromium.org>
> Addresses-Coverity-ID: 1461658 ("Memory - corruptions")
> Signed-off-by: Peng Fan <peng.fan@nxp.com>
> ---
> 
> V2:
>  I not include the fixes tag, since this patch still in next tree.
> 
>  drivers/mailbox/imx-mailbox.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/mailbox/imx-mailbox.c b/drivers/mailbox/imx-mailbox.c
> index 7906624a731c..c2398cb63ea0 100644
> --- a/drivers/mailbox/imx-mailbox.c
> +++ b/drivers/mailbox/imx-mailbox.c
> @@ -154,12 +154,12 @@ static int imx_mu_scu_tx(struct imx_mu_priv *priv,
>  
>  	switch (cp->type) {
>  	case IMX_MU_TYPE_TX:
> -		if (msg->hdr.size > sizeof(*msg)) {
> +		if (msg->hdr.size > (sizeof(*msg) / 4)) {

No need for the parenthesis. Maybe a comment would be helpful here,
something like:

	/*
	 * msg->hdr.size specifies the number of u32 words while sizeof
	 * yields bytes.
	 */

>  			/*
>  			 * The real message size can be different to
>  			 * struct imx_sc_rpc_msg_max size
>  			 */
> -			dev_err(priv->dev, "Exceed max msg size (%zu) on TX, got: %i\n", sizeof(*msg), msg->hdr.size);
> +			dev_err(priv->dev, "Exceed max msg size (%zu) on TX, got: %i\n", sizeof(*msg) / 4, msg->hdr.size);

The unit here is also "number of u32 words", maybe bytes is more
natural? And I suggesting specifying the unit in the error message.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |

RE: [PATCH] mailbox: imx-mailbox: fix scu msg header size check

[Peng Fan]

> Subject: Re: [PATCH] mailbox: imx-mailbox: fix scu msg header size check
> 
> On Tue, Apr 14, 2020 at 04:10:26PM +0800, peng.fan@nxp.com wrote:
> > From: Peng Fan <peng.fan@nxp.com>
> >
> > The i.MX8 SCU message header size is the number of "u32" elements, not
> > "u8", so fix the check.
> >
> > Reported-by: coverity-bot <keescook+coverity-bot@chromium.org>
> > Addresses-Coverity-ID: 1461658 ("Memory - corruptions")
> > Signed-off-by: Peng Fan <peng.fan@nxp.com>
> > ---
> >
> > V2:
> >  I not include the fixes tag, since this patch still in next tree.
> >
> >  drivers/mailbox/imx-mailbox.c | 8 ++++----
> >  1 file changed, 4 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/mailbox/imx-mailbox.c
> > b/drivers/mailbox/imx-mailbox.c index 7906624a731c..c2398cb63ea0
> > 100644
> > --- a/drivers/mailbox/imx-mailbox.c
> > +++ b/drivers/mailbox/imx-mailbox.c
> > @@ -154,12 +154,12 @@ static int imx_mu_scu_tx(struct imx_mu_priv
> > *priv,
> >
> >  	switch (cp->type) {
> >  	case IMX_MU_TYPE_TX:
> > -		if (msg->hdr.size > sizeof(*msg)) {
> > +		if (msg->hdr.size > (sizeof(*msg) / 4)) {
> 
> No need for the parenthesis. Maybe a comment would be helpful here,
> something like:
> 
> 	/*
> 	 * msg->hdr.size specifies the number of u32 words while sizeof
> 	 * yields bytes.
> 	 */

V2 will have the update.

> 
> >  			/*
> >  			 * The real message size can be different to
> >  			 * struct imx_sc_rpc_msg_max size
> >  			 */
> > -			dev_err(priv->dev, "Exceed max msg size (%zu) on TX,
> got: %i\n", sizeof(*msg), msg->hdr.size);
> > +			dev_err(priv->dev, "Exceed max msg size (%zu) on TX,
> got: %i\n",
> > +sizeof(*msg) / 4, msg->hdr.size);
> 
> The unit here is also "number of u32 words", maybe bytes is more natural?

ok. Will change to msg->hdr.size << 2 keeping sizeof(*msg).

> And I suggesting specifying the unit in the error message.

Is this ok to you?
dev_err(priv->dev, "Exceed max msg size (%zu) on TX, got: %i, 
msg->hdr.size: %i\n", sizeof(*msg), msg->hdr.size << 2, msg->hdr.size);

Thanks,
Peng.

> 
> Best regards
> Uwe
> 
> --
> Pengutronix e.K.                           | Uwe Kleine-König
> |
> Industrial Linux Solutions                 |
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> pengutronix.de%2F&amp;data=02%7C01%7Cpeng.fan%40nxp.com%7Ca6a32
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Re: [PATCH] mailbox: imx-mailbox: fix scu msg header size check

[Uwe Kleine-König]

On Tue, Apr 14, 2020 at 08:40:19AM +0000, Peng Fan wrote:
> > Subject: Re: [PATCH] mailbox: imx-mailbox: fix scu msg header size check
> > 
> > On Tue, Apr 14, 2020 at 04:10:26PM +0800, peng.fan@nxp.com wrote:
> > > From: Peng Fan <peng.fan@nxp.com>
> > >
> > > The i.MX8 SCU message header size is the number of "u32" elements, not
> > > "u8", so fix the check.
> > >
> > > Reported-by: coverity-bot <keescook+coverity-bot@chromium.org>
> > > Addresses-Coverity-ID: 1461658 ("Memory - corruptions")
> > > Signed-off-by: Peng Fan <peng.fan@nxp.com>
> > > ---
> > >
> > > V2:
> > >  I not include the fixes tag, since this patch still in next tree.
> > >
> > >  drivers/mailbox/imx-mailbox.c | 8 ++++----
> > >  1 file changed, 4 insertions(+), 4 deletions(-)
> > >
> > > diff --git a/drivers/mailbox/imx-mailbox.c
> > > b/drivers/mailbox/imx-mailbox.c index 7906624a731c..c2398cb63ea0
> > > 100644
> > > --- a/drivers/mailbox/imx-mailbox.c
> > > +++ b/drivers/mailbox/imx-mailbox.c
> > > @@ -154,12 +154,12 @@ static int imx_mu_scu_tx(struct imx_mu_priv
> > > *priv,
> > >
> > >  	switch (cp->type) {
> > >  	case IMX_MU_TYPE_TX:
> > > -		if (msg->hdr.size > sizeof(*msg)) {
> > > +		if (msg->hdr.size > (sizeof(*msg) / 4)) {
> > 
> > No need for the parenthesis. Maybe a comment would be helpful here,
> > something like:
> > 
> > 	/*
> > 	 * msg->hdr.size specifies the number of u32 words while sizeof
> > 	 * yields bytes.
> > 	 */
> 
> V2 will have the update.
> 
> > 
> > >  			/*
> > >  			 * The real message size can be different to
> > >  			 * struct imx_sc_rpc_msg_max size
> > >  			 */
> > > -			dev_err(priv->dev, "Exceed max msg size (%zu) on TX,
> > got: %i\n", sizeof(*msg), msg->hdr.size);
> > > +			dev_err(priv->dev, "Exceed max msg size (%zu) on TX,
> > got: %i\n",
> > > +sizeof(*msg) / 4, msg->hdr.size);
> > 
> > The unit here is also "number of u32 words", maybe bytes is more natural?
> 
> ok. Will change to msg->hdr.size << 2 keeping sizeof(*msg).
> 
> > And I suggesting specifying the unit in the error message.
> 
> Is this ok to you?
> dev_err(priv->dev, "Exceed max msg size (%zu) on TX, got: %i, 
> msg->hdr.size: %i\n", sizeof(*msg), msg->hdr.size << 2, msg->hdr.size);

I'd prefer:

	dev_err(priv->dev, "Maximal message size (%zu bytes) exceeded on TX; got: %i bytes\n"

. Duplicating the value doesn't add much value.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |