diff --git a/grub-core/video/readers/jpeg.c b/grub-core/video/readers/jpeg.c index 1df1171d7879f8aa9b7ba80c43fe59160158213b..97a533b24f34856f705aef98ae91465ef114af84 100644 --- a/grub-core/video/readers/jpeg.c +++ b/grub-core/video/readers/jpeg.c @@ -23,6 +23,7 @@ #include <grub/mm.h> #include <grub/misc.h> #include <grub/bufio.h> +#include <grub/safemath.h> GRUB_MOD_LICENSE ("GPLv3+"); @@ -693,6 +694,7 @@ static grub_err_t grub_jpeg_decode_data (struct grub_jpeg_data *data) { unsigned c1, vb, hb, nr1, nc1; + unsigned stride_a, stride_b, stride; int rst = data->dri; grub_err_t err = GRUB_ERR_NONE; @@ -705,8 +707,14 @@ grub_jpeg_decode_data (struct grub_jpeg_data *data) return grub_error (GRUB_ERR_BAD_FILE_TYPE, "jpeg: attempted to decode data before start of stream"); + if (grub_mul(vb, data->image_width, &stride_a) || + grub_mul(hb, nc1, &stride_b) || + grub_sub(stride_a, stride_b, &stride)) + return grub_error (GRUB_ERR_BAD_FILE_TYPE, + "jpeg: cannot decode image with these dimensions"); + for (; data->r1 < nr1 && (!data->dri || rst); - data->r1++, data->bitmap_ptr += (vb * data->image_width - hb * nc1) * 3) + data->r1++, data->bitmap_ptr += stride * 3) for (c1 = 0; c1 < nc1 && (!data->dri || rst); c1++, rst--, data->bitmap_ptr += hb * 3) {