From 7f8414594e4755234fd0ca415630cfe2dfab42ce Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Fri, 19 Apr 2013 07:18:01 -0300 Subject: [PATCH] [media] media: videobuf2: fix the length check for mmap Memory maps typically require that the buffer size to be page aligned. Currently, two memops drivers do such alignment internally, but videobuf-vmalloc doesn't. Also, the buffer overflow check doesn't take it into account. So, instead of doing it at each memops driver, enforce it at VB2 core. Reported-by: Prabhakar lad Acked-by: Laurent Pinchart Acked-by: Marek Szyprowski Signed-off-by: Mauro Carvalho Chehab --- drivers/media/v4l2-core/videobuf2-core.c | 21 +++++++++++++++++---- drivers/media/v4l2-core/videobuf2-dma-contig.c | 3 --- drivers/media/v4l2-core/videobuf2-dma-sg.c | 3 ++- 3 files changed, 19 insertions(+), 8 deletions(-) diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c index 58c1744..7d833ee 100644 --- a/drivers/media/v4l2-core/videobuf2-core.c +++ b/drivers/media/v4l2-core/videobuf2-core.c @@ -54,10 +54,15 @@ static int __vb2_buf_mem_alloc(struct vb2_buffer *vb) void *mem_priv; int plane; - /* Allocate memory for all planes in this buffer */ + /* + * Allocate memory for all planes in this buffer + * NOTE: mmapped areas should be page aligned + */ for (plane = 0; plane < vb->num_planes; ++plane) { + unsigned long size = PAGE_ALIGN(q->plane_sizes[plane]); + mem_priv = call_memop(q, alloc, q->alloc_ctx[plane], - q->plane_sizes[plane], q->gfp_flags); + size, q->gfp_flags); if (IS_ERR_OR_NULL(mem_priv)) goto free; @@ -1852,6 +1857,7 @@ int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma) struct vb2_buffer *vb; unsigned int buffer, plane; int ret; + unsigned long length; if (q->memory != V4L2_MEMORY_MMAP) { dprintk(1, "Queue is not currently set up for mmap\n"); @@ -1886,8 +1892,15 @@ int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma) vb = q->bufs[buffer]; - if (vb->v4l2_planes[plane].length < (vma->vm_end - vma->vm_start)) { - dprintk(1, "Invalid length\n"); + /* + * MMAP requires page_aligned buffers. + * The buffer length was page_aligned at __vb2_buf_mem_alloc(), + * so, we need to do the same here. + */ + length = PAGE_ALIGN(vb->v4l2_planes[plane].length); + if (length < (vma->vm_end - vma->vm_start)) { + dprintk(1, + "MMAP invalid, as it would overflow buffer length\n"); return -EINVAL; } diff --git a/drivers/media/v4l2-core/videobuf2-dma-contig.c b/drivers/media/v4l2-core/videobuf2-dma-contig.c index ae35d25..fd56f25 100644 --- a/drivers/media/v4l2-core/videobuf2-dma-contig.c +++ b/drivers/media/v4l2-core/videobuf2-dma-contig.c @@ -162,9 +162,6 @@ static void *vb2_dc_alloc(void *alloc_ctx, unsigned long size, gfp_t gfp_flags) if (!buf) return ERR_PTR(-ENOMEM); - /* align image size to PAGE_SIZE */ - size = PAGE_ALIGN(size); - buf->vaddr = dma_alloc_coherent(dev, size, &buf->dma_addr, GFP_KERNEL | gfp_flags); if (!buf->vaddr) { diff --git a/drivers/media/v4l2-core/videobuf2-dma-sg.c b/drivers/media/v4l2-core/videobuf2-dma-sg.c index 59522b2..16ae3dc 100644 --- a/drivers/media/v4l2-core/videobuf2-dma-sg.c +++ b/drivers/media/v4l2-core/videobuf2-dma-sg.c @@ -55,7 +55,8 @@ static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size, gfp_t gfp_fla buf->write = 0; buf->offset = 0; buf->sg_desc.size = size; - buf->sg_desc.num_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; + /* size is already page aligned */ + buf->sg_desc.num_pages = size >> PAGE_SHIFT; buf->sg_desc.sglist = vzalloc(buf->sg_desc.num_pages * sizeof(*buf->sg_desc.sglist)); -- 2.7.4