Re: [PATCH] ethtool: fix a kernel infoleak in ethtool_get_pauseparam

[Ben Hutchings]

On Wed, 2016-06-01 at 16:39 +0200, Kangjie Lu wrote:
> The field autoneg of pauseparam is not initialized in some
> implementations of get_pauseparam(),

Nonsense. ÂThe current implementation initialises all fields. Â(If
there was padding in the structure, this change would be needed to
guarantee that the padding was initialised. ÂBut there isn't.)

Ben.

>  but the whole object is
> copied to userland.
> 
> Signed-off-by: Kangjie Lu <kjlu@xxxxxxxxxx>
> ---
> Ânet/core/ethtool.c | 5 ++++-
> Â1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/net/core/ethtool.c b/net/core/ethtool.c
> index f426c5a..84544bd 100644
> --- a/net/core/ethtool.c
> +++ b/net/core/ethtool.c
> @@ -1723,7 +1723,10 @@ static noinline_for_stack int
> ethtool_set_channels(struct net_device *dev,
> Â
> Âstatic int ethtool_get_pauseparam(struct net_device *dev, void
> __user *useraddr)
> Â{
> -	struct ethtool_pauseparam pauseparam = { ETHTOOL_GPAUSEPARAM
> };
> +	struct ethtool_pauseparam pauseparam;
> +
> +	memset(&pauseparam, 0, sizeof(pauseparam));
> +	pauseparam.cmd = ETHTOOL_GPAUSEPARAM;
> Â
> Â	if (!dev->ethtool_ops->get_pauseparam)
> Â		return -EOPNOTSUPP;
-- 
Ben Hutchings
To err is human; to really foul things up requires a computer.

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