From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Frediano Ziglio Date: Tue, 8 Sep 2015 13:09:35 +0100 Subject: [PATCH] Prevent 32 bit integer overflow in bitmap_consistent The overflow may lead to buffer overflow as the row size computed from width (bitmap->x) can be bigger than the size in bytes (bitmap->stride). This can make spice-server accept the invalid sizes. Signed-off-by: Frediano Ziglio Acked-by: Christophe Fergeau --- server/red_parse_qxl.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/server/red_parse_qxl.c b/server/red_parse_qxl.c index 01cba0f..3385f52 100644 --- a/server/red_parse_qxl.c +++ b/server/red_parse_qxl.c @@ -357,11 +357,12 @@ static const char *bitmap_format_to_string(int format) return "unknown"; } -static const int MAP_BITMAP_FMT_TO_BITS_PER_PIXEL[] = {0, 1, 1, 4, 4, 8, 16, 24, 32, 32, 8}; +static const unsigned int MAP_BITMAP_FMT_TO_BITS_PER_PIXEL[] = + {0, 1, 1, 4, 4, 8, 16, 24, 32, 32, 8}; static int bitmap_consistent(SpiceBitmap *bitmap) { - int bpp; + unsigned int bpp; if (bitmap->format >= SPICE_N_ELEMENTS(MAP_BITMAP_FMT_TO_BITS_PER_PIXEL)) { spice_warning("wrong format specified for image\n"); @@ -370,8 +371,8 @@ static int bitmap_consistent(SpiceBitmap *bitmap) bpp = MAP_BITMAP_FMT_TO_BITS_PER_PIXEL[bitmap->format]; - if (bitmap->stride < ((bitmap->x * bpp + 7) / 8)) { - spice_error("image stride too small for width: %d < ((%d * %d + 7) / 8) (%s=%d)\n", + if (bitmap->stride < (((uint64_t) bitmap->x * bpp + 7u) / 8u)) { + spice_warning("image stride too small for width: %d < ((%d * %d + 7) / 8) (%s=%d)\n", bitmap->stride, bitmap->x, bpp, bitmap_format_to_string(bitmap->format), bitmap->format);