Re: [PATCH] sb1000: prevent a potential NULL pointer dereference in sb1000_dev_ioctl()

From: Michael Buesch
Date: Sun Jul 29 2007 - 14:48:45 EST


On Sunday 29 July 2007 20:34:46 Satyam Sharma wrote:
> (2) !(dev->flags & IFF_UP) is bogus because the functions of this ioctl
> can (and should) be allowed even when the interface is not up and running.

Are you _sure_? This function does poke with the device hardware.
It might return crap or even machinecheck when not initialized.
Hardware is probably powered down, if not IFF_UP. (I don't know if that's
the case here, though).

> drivers/net/sb1000.c | 3 ---
> 1 files changed, 0 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/net/sb1000.c b/drivers/net/sb1000.c
> index 1de3eec..f60fe98 100644
> --- a/drivers/net/sb1000.c
> +++ b/drivers/net/sb1000.c
> @@ -993,9 +993,6 @@ static int sb1000_dev_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
> unsigned int stats[5];
> struct sb1000_private *lp = netdev_priv(dev);
>
> - if (!(dev && dev->flags & IFF_UP))
> - return -ENODEV;
> -


--
Greetings Michael.
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