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

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

[Vasiliy Kulikov]

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@gmail.com>
---
 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,
-- 
1.7.0.4

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

[scameron]

On Sat, Oct 23, 2010 at 12:25:11PM +0400, Vasiliy Kulikov wrote:
> 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.

leaking of contents of kernel stack memory to userland,
not a memory leak, just to be clear.

> 
> Signed-off-by: Vasiliy Kulikov <segooon@gmail.com>
> ---
>  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,
> -- 
> 1.7.0.4

Ack.  

Thanks.

I would think hpsa needs a similar fix, and also cciss_ioctl32_big_passthru().
I suppose it's possible the big passthru alignment just "works out", (I haven't
checked), but even if that is the case, probably best not to rely on such an
accident,

-- steve

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

[Miller, Mike (OS Dev)]

 

> -----Original Message-----
> From: Vasiliy Kulikov [mailto:segooon@gmail.com] 
> Sent: Saturday, October 23, 2010 3:25 AM
> To: kernel-janitors@vger.kernel.org
> Cc: Miller, Mike (OS Dev); Jens Axboe; Stephen M. Cameron; 
> Andrew Morton; ISS StorageDev; linux-kernel@vger.kernel.org
> 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@gmail.com>
> ---
>  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@hp.com>

> 1.7.0.4
> 
> 

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

[Miller, Mike (OS Dev)]

> -----Original Message-----
> From: Miller, Mike (OS Dev)
> Sent: Monday, October 25, 2010 9:41 AM
> To: Vasiliy Kulikov; kernel-janitors@vger.kernel.org
> Cc: Jens Axboe; Stephen M. Cameron; Andrew Morton; ISS StorageDev;
> linux-kernel@vger.kernel.org
> Subject: RE: [PATCH 1/2] block: cciss: fix information leak to userland
> 
> 
> 
> > -----Original Message-----
> > From: Vasiliy Kulikov [mailto:segooon@gmail.com]
> > Sent: Saturday, October 23, 2010 3:25 AM
> > To: kernel-janitors@vger.kernel.org
> > Cc: Miller, Mike (OS Dev); Jens Axboe; Stephen M. Cameron;
> > Andrew Morton; ISS StorageDev; linux-kernel@vger.kernel.org
> > 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@gmail.com>
> > ---
> >  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@hp.com>

BTW: this change needs to go into the cciss_ioctl32_big_passthru and the other passthru ioctls, also.

-- mikem

> 
> > 1.7.0.4
> >
> >

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@vger.kernel.org
> > Cc: Jens Axboe; Stephen M. Cameron; Andrew Morton; ISS StorageDev;
> > linux-kernel@vger.kernel.org
> > Subject: RE: [PATCH 1/2] block: cciss: fix information leak to userland
> > 
> > 
> > 
> > > -----Original Message-----
> > > From: Vasiliy Kulikov [mailto:segooon@gmail.com]
> > > Sent: Saturday, October 23, 2010 3:25 AM
> > > To: kernel-janitors@vger.kernel.org
> > > Cc: Miller, Mike (OS Dev); Jens Axboe; Stephen M. Cameron;
> > > Andrew Morton; ISS StorageDev; linux-kernel@vger.kernel.org
> > > 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@gmail.com>
> > > ---
> > >  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@hp.com>
> 
> 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