From 876d516311c1538a7d29f2abec48b7cda0645eea Mon Sep 17 00:00:00 2001 From: =?utf8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= Date: Tue, 17 Feb 2015 17:30:51 +0100 Subject: [PATCH] spice: fix invalid memory access to vga.vram MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit vga_common_init() doesn't allow more than 256 MiB vram size and silently shrinks any larger value. qxl_dirty_surfaces() used the unshrinked size via qxl->shadow_rom.surface0_area_size when accessing the memory, which resulted in segfault. Add a workaround for this case and an assert if it happens again. We have to bump the vga memory limit too, because 256 MiB wouldn't have allowed 8k (it requires more than 128 MiB). 1024 MiB doesn't work, but 512 MiB seems fine. Proposed-by: Gerd Hoffmann Signed-off-by: Radim Krčmář Signed-off-by: Gerd Hoffmann --- hw/display/qxl.c | 8 ++++++++ hw/display/vga.c | 4 ++-- 2 files changed, 10 insertions(+), 2 deletions(-) diff --git a/hw/display/qxl.c b/hw/display/qxl.c index 6e9079783e..92f2d5025d 100644 --- a/hw/display/qxl.c +++ b/hw/display/qxl.c @@ -370,6 +370,8 @@ static void init_qxl_rom(PCIQXLDevice *d) num_pages -= surface0_area_size; num_pages = num_pages / QXL_PAGE_SIZE; + assert(ram_header_size + surface0_area_size <= d->vga.vram_size); + rom->draw_area_offset = cpu_to_le32(0); rom->surface0_area_size = cpu_to_le32(surface0_area_size); rom->pages_offset = cpu_to_le32(surface0_area_size); @@ -1883,6 +1885,12 @@ static void qxl_init_ramsize(PCIQXLDevice *qxl) if (qxl->vgamem_size_mb < 8) { qxl->vgamem_size_mb = 8; } + /* XXX: we round vgamem_size_mb up to a nearest power of two and it must be + * less than vga_common_init()'s maximum on qxl->vga.vram_size (512 now). + */ + if (qxl->vgamem_size_mb > 256) { + qxl->vgamem_size_mb = 256; + } qxl->vgamem_size = qxl->vgamem_size_mb * 1024 * 1024; /* vga ram (bar 0, total) */ diff --git a/hw/display/vga.c b/hw/display/vga.c index c8c49abc6e..6e4ca7e9ab 100644 --- a/hw/display/vga.c +++ b/hw/display/vga.c @@ -2121,10 +2121,10 @@ void vga_common_init(VGACommonState *s, Object *obj, bool global_vmstate) expand4to8[i] = v; } - /* valid range: 1 MB -> 256 MB */ + /* valid range: 1 MB -> 512 MB */ s->vram_size = 1024 * 1024; while (s->vram_size < (s->vram_size_mb << 20) && - s->vram_size < (256 << 20)) { + s->vram_size < (512 << 20)) { s->vram_size <<= 1; } s->vram_size_mb = s->vram_size >> 20; -- 2.11.4.GIT