Re: [PATCH 1/2] block: cciss: fix information leak to userland

[Vasiliy Kulikov]

Hi Mike,

On Mon, Oct 25, 2010 at 16:36 +0000, Miller, Mike (OS Dev) wrote:
> 
> 
> > -----Original Message-----
> > From: Miller, Mike (OS Dev)
> > Sent: Monday, October 25, 2010 9:41 AM
> > To: Vasiliy Kulikov; kernel-janitors@xxxxxxxxxxxxxxx
> > Cc: Jens Axboe; Stephen M. Cameron; Andrew Morton; ISS StorageDev;
> > linux-kernel@xxxxxxxxxxxxxxx
> > Subject: RE: [PATCH 1/2] block: cciss: fix information leak to userland
> > 
> > 
> > 
> > > -----Original Message-----
> > > From: Vasiliy Kulikov [mailto:segooon@xxxxxxxxx]
> > > Sent: Saturday, October 23, 2010 3:25 AM
> > > To: kernel-janitors@xxxxxxxxxxxxxxx
> > > Cc: Miller, Mike (OS Dev); Jens Axboe; Stephen M. Cameron;
> > > Andrew Morton; ISS StorageDev; linux-kernel@xxxxxxxxxxxxxxx
> > > Subject: [PATCH 1/2] block: cciss: fix information leak to userland
> > >
> > > Structure IOCTL_Command_struct is copied to userland with
> > > some padding fields at the end of the struct unitialized.
> > > It leads to leaking of stack memory.
> > >
> > > Signed-off-by: Vasiliy Kulikov <segooon@xxxxxxxxx>
> > > ---
> > >  drivers/block/cciss.c |    1 +
> > >  1 files changed, 1 insertions(+), 0 deletions(-)
> > >
> > > diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
> > > index 762a81a..cd08324 100644
> > > --- a/drivers/block/cciss.c
> > > +++ b/drivers/block/cciss.c
> > > @@ -1142,6 +1142,7 @@ static int
> > > cciss_ioctl32_passthru(struct block_device *bdev, fmode_t mode,
> > >  	int err;
> > >  	u32 cp;
> > >
> > > +	memset(&arg64, 0, sizeof(arg64));
> > >  	err = 0;
> > >  	err |=
> > >  	    copy_from_user(&arg64.LUN_info, &arg32->LUN_info,
> > > --
> > 
> > Acked-by: Mike Miller <mike.miller@xxxxxx>
> 
> BTW: this change needs to go into the cciss_ioctl32_big_passthru

I've sent the patch, thanks.

> and the other passthru ioctls, also.

I don't see problems with them, they do copy_from_user() before
filling the structure.

> 
> -- mikem
> 
> > 
> > > 1.7.0.4
> > >
> > >

Thanks,

-- 
Vasiliy
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