2021-03-10 07:42:12

by Ricardo Ribalda

Subject: [PATCH] media: videobuf2: Fix integer overrun in vb2_mmap

The plane_length is an unsigned integer. So, if we have a size of
0xffffffff bytes we incorrectly allocate 0 bytes instead of 1 << 32.

Suggested-by: Sergey Senozhatsky <[email protected]>
Cc: [email protected]
Fixes: 7f8414594e47 ("[media] media: videobuf2: fix the length check for mmap")
Signed-off-by: Ricardo Ribalda <[email protected]>
---
drivers/media/common/videobuf2/videobuf2-core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
index 543da515c761..876db5886867 100644
--- a/drivers/media/common/videobuf2/videobuf2-core.c
+++ b/drivers/media/common/videobuf2/videobuf2-core.c
@@ -2256,7 +2256,7 @@ int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
* The buffer length was page_aligned at __vb2_buf_mem_alloc(),
* so, we need to do the same here.
*/
- length = PAGE_ALIGN(vb->planes[plane].length);
+ length = PAGE_ALIGN((unsigned int)vb->planes[plane].length);
if (length < (vma->vm_end - vma->vm_start)) {
dprintk(q, 1,
"MMAP invalid, as it would overflow buffer length\n");
--
2.30.1.766.gb4fecdf3b7-goog

2021-03-10 07:48:26

by Sergey Senozhatsky

Subject: Re: [PATCH] media: videobuf2: Fix integer overrun in vb2_mmap

On (21/03/10 08:40), Ricardo Ribalda wrote:
>
> The plane_length is an unsigned integer. So, if we have a size of
> 0xffffffff bytes we incorrectly allocate 0 bytes instead of 1 << 32.
>
> Suggested-by: Sergey Senozhatsky <[email protected]>
> Cc: [email protected]
> Fixes: 7f8414594e47 ("[media] media: videobuf2: fix the length check for mmap")
> Signed-off-by: Ricardo Ribalda <[email protected]>


FWIF,
Reviewed-by: Sergey Senozhatsky <[email protected]>

2021-03-10 07:49:23

by Jiri Slaby

Subject: Re: [PATCH] media: videobuf2: Fix integer overrun in vb2_mmap

On 10. 03. 21, 8:40, Ricardo Ribalda wrote:
> The plane_length is an unsigned integer. So, if we have a size of
> 0xffffffff bytes we incorrectly allocate 0 bytes instead of 1 << 32.
>
> Suggested-by: Sergey Senozhatsky <[email protected]>
> Cc: [email protected]
> Fixes: 7f8414594e47 ("[media] media: videobuf2: fix the length check for mmap")
> Signed-off-by: Ricardo Ribalda <[email protected]>
> ---
> drivers/media/common/videobuf2/videobuf2-core.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
> index 543da515c761..876db5886867 100644
> --- a/drivers/media/common/videobuf2/videobuf2-core.c
> +++ b/drivers/media/common/videobuf2/videobuf2-core.c
> @@ -2256,7 +2256,7 @@ int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
> * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
> * so, we need to do the same here.
> */
> - length = PAGE_ALIGN(vb->planes[plane].length);
> + length = PAGE_ALIGN((unsigned int)vb->planes[plane].length);

Hi,

I fail to see how case from uint to uint helps -- IOW, did you mean ulong?

regards,
--
js
suse labs

2021-03-10 07:53:00

by Ricardo Ribalda

Subject: Re: [PATCH] media: videobuf2: Fix integer overrun in vb2_mmap

On Wed, Mar 10, 2021 at 8:47 AM Jiri Slaby <[email protected]> wrote:
>
> On 10. 03. 21, 8:40, Ricardo Ribalda wrote:
> > The plane_length is an unsigned integer. So, if we have a size of
> > 0xffffffff bytes we incorrectly allocate 0 bytes instead of 1 << 32.
> >
> > Suggested-by: Sergey Senozhatsky <[email protected]>
> > Cc: [email protected]
> > Fixes: 7f8414594e47 ("[media] media: videobuf2: fix the length check for mmap")
> > Signed-off-by: Ricardo Ribalda <[email protected]>
> > ---
> > drivers/media/common/videobuf2/videobuf2-core.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
> > index 543da515c761..876db5886867 100644
> > --- a/drivers/media/common/videobuf2/videobuf2-core.c
> > +++ b/drivers/media/common/videobuf2/videobuf2-core.c
> > @@ -2256,7 +2256,7 @@ int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
> > * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
> > * so, we need to do the same here.
> > */
> > - length = PAGE_ALIGN(vb->planes[plane].length);
> > + length = PAGE_ALIGN((unsigned int)vb->planes[plane].length);
>
> Hi,
>
> I fail to see how case from uint to uint helps -- IOW, did you mean ulong?

Ups... my bad :(

Let me send a v2

>
> regards,
> --
> js
> suse labs



--
Ricardo Ribalda