From: Yong Zhi Date: Thu, 4 Jan 2018 02:57:16 +0000 (-0500) Subject: media: intel-ipu3: cio2: fix a crash with out-of-bounds access X-Git-Tag: v4.16-rc1~57^2~49 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=c7cbef1fdb5480e9f39e8db64ac32ed8e1984adf;p=thirdparty%2Fkernel%2Flinux.git media: intel-ipu3: cio2: fix a crash with out-of-bounds access When dmabuf is used for BLOB type frame, the frame buffers allocated by gralloc will hold more pages than the valid frame data due to height alignment. In this case, the page numbers in sg list could exceed the FBPT upper limit value - max_lops(8)*1024 to cause crash. Limit the LOP access to the valid data length to avoid FBPT sub-entries overflow. Signed-off-by: Yong Zhi Signed-off-by: Cao Bing Bu Signed-off-by: Sakari Ailus Signed-off-by: Mauro Carvalho Chehab --- diff --git a/drivers/media/pci/intel/ipu3/ipu3-cio2.c b/drivers/media/pci/intel/ipu3/ipu3-cio2.c index 9b9ad7771dda1..9377f880b8f6d 100644 --- a/drivers/media/pci/intel/ipu3/ipu3-cio2.c +++ b/drivers/media/pci/intel/ipu3/ipu3-cio2.c @@ -838,8 +838,9 @@ static int cio2_vb2_buf_init(struct vb2_buffer *vb) container_of(vb, struct cio2_buffer, vbb.vb2_buf); static const unsigned int entries_per_page = CIO2_PAGE_SIZE / sizeof(u32); - unsigned int pages = DIV_ROUND_UP(vb->planes[0].length, CIO2_PAGE_SIZE); - unsigned int lops = DIV_ROUND_UP(pages + 1, entries_per_page); + unsigned int pages = DIV_ROUND_UP(vb->planes[0].length, + CIO2_PAGE_SIZE) + 1; + unsigned int lops = DIV_ROUND_UP(pages, entries_per_page); struct sg_table *sg; struct sg_page_iter sg_iter; int i, j; @@ -869,6 +870,8 @@ static int cio2_vb2_buf_init(struct vb2_buffer *vb) i = j = 0; for_each_sg_page(sg->sgl, &sg_iter, sg->nents, 0) { + if (!pages--) + break; b->lop[i][j] = sg_page_iter_dma_address(&sg_iter) >> PAGE_SHIFT; j++; if (j == entries_per_page) {