[U-Boot] [PATCH] phy: Fix u-boot coruption when fixed-phy is used

[Stefan Roese]

On 19.12.18 16:57, Michal Simek wrote:
> When fixed-link phy is used subnode offset is used as phy address. This
> number is bigger then space allocated for bus structure (allocated via
> mdio_alloc).
> bus->phymap[] array has PHY_MAX_ADDR size (32).
> That's why writing bus->phymap[addr] where addr is < 0 or > PHY_MAX_ADDR
> is causing write to memory which can caused full U-Boot crash.
> 
> The patch is checking if address is in correct range.
> 
> Signed-off-by: Michal Simek <michal.simek at xilinx.com>
> ---
> 
> search_for_existing_phy() is using this array but there is if check
> already that's why it shouldn't be a big deal.
> 
> ---
>   drivers/net/phy/phy.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
> index e837eb7688cc..cda4caa8034d 100644
> --- a/drivers/net/phy/phy.c
> +++ b/drivers/net/phy/phy.c
> @@ -656,7 +656,8 @@ static struct phy_device *phy_device_create(struct mii_dev *bus, int addr,
>   
>   	phy_probe(dev);
>   
> -	bus->phymap[addr] = dev;
> +	if (addr >= 0 && addr < PHY_MAX_ADDR)
> +		bus->phymap[addr] = dev;

How about adding some error / warning print in the else path here?

Thanks,
Stefan