| Message ID | 20210310074028.1042475-1-ribalda@chromium.org |
|---|---|
| State | New |
| Headers | show |
| Series | media: videobuf2: Fix integer overrun in vb2_mmap | expand |
On Wed, Mar 10, 2021 at 8:47 AM Jiri Slaby <jslaby@suse.cz> 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 <senozhatsky@chromium.org> > > Cc: stable@vger.kernel.org > > Fixes: 7f8414594e47 ("[media] media: videobuf2: fix the length check for mmap") > > Signed-off-by: Ricardo Ribalda <ribalda@chromium.org> > > --- > > 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
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");
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 <senozhatsky@chromium.org> Cc: stable@vger.kernel.org Fixes: 7f8414594e47 ("[media] media: videobuf2: fix the length check for mmap") Signed-off-by: Ricardo Ribalda <ribalda@chromium.org> --- drivers/media/common/videobuf2/videobuf2-core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)