Re: [PATCH 6/8] char: synclink: fix information leak to userland

From: Jiri Slaby
Date: Sun Oct 17 2010 - 11:34:43 EST


On 10/17/2010 04:41 PM, Vasiliy Kulikov wrote:
> Structure new_line is copied to userland with some padding fields unitialized.
> It leads to leaking of stack memory.

I think your tool has a bug. I must admit I fail to see the padding
which would cause leaks. Could you elaborate?

> Signed-off-by: Vasiliy Kulikov <segooon@xxxxxxxxx>
> ---
> Compile tested.
>
> drivers/char/synclink.c | 2 ++
> 1 files changed, 2 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/char/synclink.c b/drivers/char/synclink.c
> index 3a6824f..abd0867 100644
> --- a/drivers/char/synclink.c
> +++ b/drivers/char/synclink.c
> @@ -7846,6 +7846,8 @@ static int hdlcdev_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
> if (cmd != SIOCWANDEV)
> return hdlc_ioctl(dev, ifr, cmd);
>
> + memset(&new_line, 0, size);
> +
> switch(ifr->ifr_settings.type) {
> case IF_GET_IFACE: /* return current sync_serial_settings */
>


--
js
suse labs
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