On 06.06.23 11:33, Sascha Hauer wrote:
> On Mon, Jun 05, 2023 at 08:29:36AM +0200, Ahmad Fatoum wrote:
>> The MAC address will be written to two 32-bit registers. Because
>> MAC_ADDR_LEN == 6, this meant two bytes out-of-bounds where written to
>> the hardware register. Fix this by having them be in-bound and always
>> initialized to zero.
>>
>> Signed-off-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
>> ---
>> drivers/net/gianfar.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/net/gianfar.c b/drivers/net/gianfar.c
>> index 4b374b4a50de..10a95324920b 100644
>> --- a/drivers/net/gianfar.c
>> +++ b/drivers/net/gianfar.c
>> @@ -234,7 +234,7 @@ static int gfar_set_ethaddr(struct eth_device *edev, const unsigned char *mac)
>> {
>> struct gfar_private *priv = edev->priv;
>> void __iomem *regs = priv->regs;
>> - char tmpbuf[MAC_ADDR_LEN];
>> + char tmpbuf[8] = {};
>
> I would prefer to adopt the Linux commit fixing this code which apart
> from the out-of-bounds access also has endianess fixes and makes the
> code simpler:
>
> ---------------------------8<-----------------------------------
>
> From 35cc52aacd65886a2ae46e68f727cadd09a3e8f2 Mon Sep 17 00:00:00 2001
> From: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
> Date: Tue, 6 Jun 2023 11:29:51 +0200
> Subject: [PATCH] net: gianfar: make MAC addr setup endian safe, cleanup
>
> This is an adoption of Linux commit:
>
> | commit 83bfc3c4765c35ef0dfff8a3d6dedab88f3f50ea
> | Author: Claudiu Manoil <claudiu.manoil@xxxxxxxxxxxxx>
> | Date: Tue Oct 7 10:44:33 2014 +0300
> |
> | gianfar: Make MAC addr setup endian safe, cleanup
> |
> | Fix the 32-bit memory access that is not endian safe,
> | i.e. not giving the desired byte layout for a LE CPU:
> | tempval = *((u32 *) (tmpbuf + 4)), where 'char tmpbuf[]'.
> |
> | Get rid of rendundant local vars (tmpbuf[] and idx) and
> | forced casts. Cleanup comments.
> |
> | Signed-off-by: Claudiu Manoil <claudiu.manoil@xxxxxxxxxxxxx>
> | Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
>
> Signed-off-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
Reviewed-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
> ---
> drivers/net/gianfar.c | 10 ++--------
> 1 file changed, 2 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/net/gianfar.c b/drivers/net/gianfar.c
> index 4b374b4a50..1a07059db4 100644
> --- a/drivers/net/gianfar.c
> +++ b/drivers/net/gianfar.c
> @@ -234,19 +234,13 @@ static int gfar_set_ethaddr(struct eth_device *edev, const unsigned char *mac)
> {
> struct gfar_private *priv = edev->priv;
> void __iomem *regs = priv->regs;
> - char tmpbuf[MAC_ADDR_LEN];
> uint tempval;
> - int ix;
> -
> - for (ix = 0; ix < MAC_ADDR_LEN; ix++)
> - tmpbuf[MAC_ADDR_LEN - 1 - ix] = mac[ix];
>
> - tempval = (tmpbuf[0] << 24) | (tmpbuf[1] << 16) | (tmpbuf[2] << 8) |
> - tmpbuf[3];
> + tempval = (mac[5] << 24) | (mac[4] << 16) | (mac[3] << 8) | mac[2];
>
> out_be32(regs + GFAR_MACSTRADDR1_OFFSET, tempval);
>
> - tempval = *((uint *)(tmpbuf + 4));
> + tempval = (mac[1] << 24) | (mac[0] << 16);
>
> out_be32(regs + GFAR_MACSTRADDR2_OFFSET, tempval);
>
--
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