From d2ba7ecb348d3b996fcd920cf1ca7b72722c1dfd Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Wed, 10 Feb 2016 17:17:39 +0100 Subject: [PATCH 1/2] cirrus_vga: fix off-by-one in blit_region_is_unsafe The "max" value is being compared with >=, but addr + width points to the first byte that will _not_ be copied. Laszlo suggested using a "greater than" comparison, instead of subtracting one like it is already done above for the height, so that max remains always positive. The mistake is "safe"---it will reject some blits, but will never cause out-of-bounds writes. Cc: Gerd Hoffmann Signed-off-by: Paolo Bonzini Reviewed-by: Laszlo Ersek Message-id: 1455121059-18280-1-git-send-email-pbonzini@redhat.com Signed-off-by: Gerd Hoffmann --- hw/display/cirrus_vga.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/hw/display/cirrus_vga.c b/hw/display/cirrus_vga.c index b6ce1c8bc7..57b91a77ca 100644 --- a/hw/display/cirrus_vga.c +++ b/hw/display/cirrus_vga.c @@ -276,14 +276,14 @@ static bool blit_region_is_unsafe(struct CirrusVGAState *s, + ((int64_t)s->cirrus_blt_height-1) * pitch; int32_t max = addr + s->cirrus_blt_width; - if (min < 0 || max >= s->vga.vram_size) { + if (min < 0 || max > s->vga.vram_size) { return true; } } else { int64_t max = addr + ((int64_t)s->cirrus_blt_height-1) * pitch + s->cirrus_blt_width; - if (max >= s->vga.vram_size) { + if (max > s->vga.vram_size) { return true; } } From 05fa1c742fd6f66978b989ded0dd981ef11c4a0c Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Tue, 20 Oct 2015 09:57:30 +0200 Subject: [PATCH 2/2] qxl: lock current_async update in qxl_soft_reset This should fix a defect report from Coverity. Signed-off-by: Gerd Hoffmann Reviewed-by: Paolo Bonzini --- hw/display/qxl.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/hw/display/qxl.c b/hw/display/qxl.c index a423deecea..919dc5cd36 100644 --- a/hw/display/qxl.c +++ b/hw/display/qxl.c @@ -1156,7 +1156,9 @@ static void qxl_soft_reset(PCIQXLDevice *d) trace_qxl_soft_reset(d->id); qxl_check_state(d); qxl_clear_guest_bug(d); + qemu_mutex_lock(&d->async_lock); d->current_async = QXL_UNDEFINED_IO; + qemu_mutex_unlock(&d->async_lock); if (d->id == 0) { qxl_enter_vga_mode(d);