diff mbox series

[6/7] sfc: Use scnprintf() for avoiding potential buffer overflow

Message ID 20200311083745.17328-7-tiwai@suse.de
State Changes Requested
Delegated to: David Miller
Headers show
Series net: Use scnprintf() for avoiding potential buffer overflow | expand

Commit Message

Takashi Iwai March 11, 2020, 8:37 a.m. UTC
Since snprintf() returns the would-be-output size instead of the
actual output size, the succeeding calls may go beyond the given
buffer limit.  Fix it by replacing with scnprintf().

Cc: Solarflare linux maintainers <linux-net-drivers@solarflare.com>
Cc: Edward Cree <ecree@solarflare.com>
Cc: Martin Habets <mhabets@solarflare.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
 drivers/net/ethernet/sfc/mcdi.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

Comments

Martin Habets March 12, 2020, 9:53 a.m. UTC | #1
Hi Takashi,

Fix looks ok, but could you please fix the alignment of the subsequent lines as well?

Thanks,
Martin

On 11/03/2020 08:37, Takashi Iwai wrote:
> Since snprintf() returns the would-be-output size instead of the
> actual output size, the succeeding calls may go beyond the given
> buffer limit.  Fix it by replacing with scnprintf().
> 
> Cc: Solarflare linux maintainers <linux-net-drivers@solarflare.com>
> Cc: Edward Cree <ecree@solarflare.com>
> Cc: Martin Habets <mhabets@solarflare.com>
> Signed-off-by: Takashi Iwai <tiwai@suse.de>
> ---
>  drivers/net/ethernet/sfc/mcdi.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/net/ethernet/sfc/mcdi.c b/drivers/net/ethernet/sfc/mcdi.c
> index 2713300343c7..ac978e24644f 100644
> --- a/drivers/net/ethernet/sfc/mcdi.c
> +++ b/drivers/net/ethernet/sfc/mcdi.c
> @@ -212,11 +212,11 @@ static void efx_mcdi_send_request(struct efx_nic *efx, unsigned cmd,
>  		 * progress on a NIC at any one time.  So no need for locking.
>  		 */
>  		for (i = 0; i < hdr_len / 4 && bytes < PAGE_SIZE; i++)
> -			bytes += snprintf(buf + bytes, PAGE_SIZE - bytes,
> +			bytes += scnprintf(buf + bytes, PAGE_SIZE - bytes,
>  					  " %08x", le32_to_cpu(hdr[i].u32[0]));
>  
>  		for (i = 0; i < inlen / 4 && bytes < PAGE_SIZE; i++)
> -			bytes += snprintf(buf + bytes, PAGE_SIZE - bytes,
> +			bytes += scnprintf(buf + bytes, PAGE_SIZE - bytes,
>  					  " %08x", le32_to_cpu(inbuf[i].u32[0]));
>  
>  		netif_info(efx, hw, efx->net_dev, "MCDI RPC REQ:%s\n", buf);
> @@ -302,14 +302,14 @@ static void efx_mcdi_read_response_header(struct efx_nic *efx)
>  		 */
>  		for (i = 0; i < hdr_len && bytes < PAGE_SIZE; i++) {
>  			efx->type->mcdi_read_response(efx, &hdr, (i * 4), 4);
> -			bytes += snprintf(buf + bytes, PAGE_SIZE - bytes,
> +			bytes += scnprintf(buf + bytes, PAGE_SIZE - bytes,
>  					  " %08x", le32_to_cpu(hdr.u32[0]));
>  		}
>  
>  		for (i = 0; i < data_len && bytes < PAGE_SIZE; i++) {
>  			efx->type->mcdi_read_response(efx, &hdr,
>  					mcdi->resp_hdr_len + (i * 4), 4);
> -			bytes += snprintf(buf + bytes, PAGE_SIZE - bytes,
> +			bytes += scnprintf(buf + bytes, PAGE_SIZE - bytes,
>  					  " %08x", le32_to_cpu(hdr.u32[0]));
>  		}
>  
> @@ -1417,7 +1417,7 @@ void efx_mcdi_print_fwver(struct efx_nic *efx, char *buf, size_t len)
>  	}
>  
>  	ver_words = (__le16 *)MCDI_PTR(outbuf, GET_VERSION_OUT_VERSION);
> -	offset = snprintf(buf, len, "%u.%u.%u.%u",
> +	offset = scnprintf(buf, len, "%u.%u.%u.%u",
>  			  le16_to_cpu(ver_words[0]), le16_to_cpu(ver_words[1]),
>  			  le16_to_cpu(ver_words[2]), le16_to_cpu(ver_words[3]));
>  
> @@ -1427,7 +1427,7 @@ void efx_mcdi_print_fwver(struct efx_nic *efx, char *buf, size_t len)
>  	if (efx_nic_rev(efx) >= EFX_REV_HUNT_A0) {
>  		struct efx_ef10_nic_data *nic_data = efx->nic_data;
>  
> -		offset += snprintf(buf + offset, len - offset, " rx%x tx%x",
> +		offset += scnprintf(buf + offset, len - offset, " rx%x tx%x",
>  				   nic_data->rx_dpcpu_fw_id,
>  				   nic_data->tx_dpcpu_fw_id);
>  
>
Takashi Iwai March 12, 2020, 11:38 a.m. UTC | #2
On Thu, 12 Mar 2020 10:53:05 +0100,
Martin Habets wrote:
> 
> Hi Takashi,
> 
> Fix looks ok, but could you please fix the alignment of the subsequent lines as well?

Yes, I'll respin with that in v2, as other people also asked for it.


thanks,

Takashi

> 
> Thanks,
> Martin
> 
> On 11/03/2020 08:37, Takashi Iwai wrote:
> > Since snprintf() returns the would-be-output size instead of the
> > actual output size, the succeeding calls may go beyond the given
> > buffer limit.  Fix it by replacing with scnprintf().
> > 
> > Cc: Solarflare linux maintainers <linux-net-drivers@solarflare.com>
> > Cc: Edward Cree <ecree@solarflare.com>
> > Cc: Martin Habets <mhabets@solarflare.com>
> > Signed-off-by: Takashi Iwai <tiwai@suse.de>
> > ---
> >  drivers/net/ethernet/sfc/mcdi.c | 12 ++++++------
> >  1 file changed, 6 insertions(+), 6 deletions(-)
> > 
> > diff --git a/drivers/net/ethernet/sfc/mcdi.c b/drivers/net/ethernet/sfc/mcdi.c
> > index 2713300343c7..ac978e24644f 100644
> > --- a/drivers/net/ethernet/sfc/mcdi.c
> > +++ b/drivers/net/ethernet/sfc/mcdi.c
> > @@ -212,11 +212,11 @@ static void efx_mcdi_send_request(struct efx_nic *efx, unsigned cmd,
> >  		 * progress on a NIC at any one time.  So no need for locking.
> >  		 */
> >  		for (i = 0; i < hdr_len / 4 && bytes < PAGE_SIZE; i++)
> > -			bytes += snprintf(buf + bytes, PAGE_SIZE - bytes,
> > +			bytes += scnprintf(buf + bytes, PAGE_SIZE - bytes,
> >  					  " %08x", le32_to_cpu(hdr[i].u32[0]));
> >  
> >  		for (i = 0; i < inlen / 4 && bytes < PAGE_SIZE; i++)
> > -			bytes += snprintf(buf + bytes, PAGE_SIZE - bytes,
> > +			bytes += scnprintf(buf + bytes, PAGE_SIZE - bytes,
> >  					  " %08x", le32_to_cpu(inbuf[i].u32[0]));
> >  
> >  		netif_info(efx, hw, efx->net_dev, "MCDI RPC REQ:%s\n", buf);
> > @@ -302,14 +302,14 @@ static void efx_mcdi_read_response_header(struct efx_nic *efx)
> >  		 */
> >  		for (i = 0; i < hdr_len && bytes < PAGE_SIZE; i++) {
> >  			efx->type->mcdi_read_response(efx, &hdr, (i * 4), 4);
> > -			bytes += snprintf(buf + bytes, PAGE_SIZE - bytes,
> > +			bytes += scnprintf(buf + bytes, PAGE_SIZE - bytes,
> >  					  " %08x", le32_to_cpu(hdr.u32[0]));
> >  		}
> >  
> >  		for (i = 0; i < data_len && bytes < PAGE_SIZE; i++) {
> >  			efx->type->mcdi_read_response(efx, &hdr,
> >  					mcdi->resp_hdr_len + (i * 4), 4);
> > -			bytes += snprintf(buf + bytes, PAGE_SIZE - bytes,
> > +			bytes += scnprintf(buf + bytes, PAGE_SIZE - bytes,
> >  					  " %08x", le32_to_cpu(hdr.u32[0]));
> >  		}
> >  
> > @@ -1417,7 +1417,7 @@ void efx_mcdi_print_fwver(struct efx_nic *efx, char *buf, size_t len)
> >  	}
> >  
> >  	ver_words = (__le16 *)MCDI_PTR(outbuf, GET_VERSION_OUT_VERSION);
> > -	offset = snprintf(buf, len, "%u.%u.%u.%u",
> > +	offset = scnprintf(buf, len, "%u.%u.%u.%u",
> >  			  le16_to_cpu(ver_words[0]), le16_to_cpu(ver_words[1]),
> >  			  le16_to_cpu(ver_words[2]), le16_to_cpu(ver_words[3]));
> >  
> > @@ -1427,7 +1427,7 @@ void efx_mcdi_print_fwver(struct efx_nic *efx, char *buf, size_t len)
> >  	if (efx_nic_rev(efx) >= EFX_REV_HUNT_A0) {
> >  		struct efx_ef10_nic_data *nic_data = efx->nic_data;
> >  
> > -		offset += snprintf(buf + offset, len - offset, " rx%x tx%x",
> > +		offset += scnprintf(buf + offset, len - offset, " rx%x tx%x",
> >  				   nic_data->rx_dpcpu_fw_id,
> >  				   nic_data->tx_dpcpu_fw_id);
> >  
> > 
>
diff mbox series

Patch

diff --git a/drivers/net/ethernet/sfc/mcdi.c b/drivers/net/ethernet/sfc/mcdi.c
index 2713300343c7..ac978e24644f 100644
--- a/drivers/net/ethernet/sfc/mcdi.c
+++ b/drivers/net/ethernet/sfc/mcdi.c
@@ -212,11 +212,11 @@  static void efx_mcdi_send_request(struct efx_nic *efx, unsigned cmd,
 		 * progress on a NIC at any one time.  So no need for locking.
 		 */
 		for (i = 0; i < hdr_len / 4 && bytes < PAGE_SIZE; i++)
-			bytes += snprintf(buf + bytes, PAGE_SIZE - bytes,
+			bytes += scnprintf(buf + bytes, PAGE_SIZE - bytes,
 					  " %08x", le32_to_cpu(hdr[i].u32[0]));
 
 		for (i = 0; i < inlen / 4 && bytes < PAGE_SIZE; i++)
-			bytes += snprintf(buf + bytes, PAGE_SIZE - bytes,
+			bytes += scnprintf(buf + bytes, PAGE_SIZE - bytes,
 					  " %08x", le32_to_cpu(inbuf[i].u32[0]));
 
 		netif_info(efx, hw, efx->net_dev, "MCDI RPC REQ:%s\n", buf);
@@ -302,14 +302,14 @@  static void efx_mcdi_read_response_header(struct efx_nic *efx)
 		 */
 		for (i = 0; i < hdr_len && bytes < PAGE_SIZE; i++) {
 			efx->type->mcdi_read_response(efx, &hdr, (i * 4), 4);
-			bytes += snprintf(buf + bytes, PAGE_SIZE - bytes,
+			bytes += scnprintf(buf + bytes, PAGE_SIZE - bytes,
 					  " %08x", le32_to_cpu(hdr.u32[0]));
 		}
 
 		for (i = 0; i < data_len && bytes < PAGE_SIZE; i++) {
 			efx->type->mcdi_read_response(efx, &hdr,
 					mcdi->resp_hdr_len + (i * 4), 4);
-			bytes += snprintf(buf + bytes, PAGE_SIZE - bytes,
+			bytes += scnprintf(buf + bytes, PAGE_SIZE - bytes,
 					  " %08x", le32_to_cpu(hdr.u32[0]));
 		}
 
@@ -1417,7 +1417,7 @@  void efx_mcdi_print_fwver(struct efx_nic *efx, char *buf, size_t len)
 	}
 
 	ver_words = (__le16 *)MCDI_PTR(outbuf, GET_VERSION_OUT_VERSION);
-	offset = snprintf(buf, len, "%u.%u.%u.%u",
+	offset = scnprintf(buf, len, "%u.%u.%u.%u",
 			  le16_to_cpu(ver_words[0]), le16_to_cpu(ver_words[1]),
 			  le16_to_cpu(ver_words[2]), le16_to_cpu(ver_words[3]));
 
@@ -1427,7 +1427,7 @@  void efx_mcdi_print_fwver(struct efx_nic *efx, char *buf, size_t len)
 	if (efx_nic_rev(efx) >= EFX_REV_HUNT_A0) {
 		struct efx_ef10_nic_data *nic_data = efx->nic_data;
 
-		offset += snprintf(buf + offset, len - offset, " rx%x tx%x",
+		offset += scnprintf(buf + offset, len - offset, " rx%x tx%x",
 				   nic_data->rx_dpcpu_fw_id,
 				   nic_data->tx_dpcpu_fw_id);