diff options
| author | Li Qiang | 2017-02-01 09:35:01 +0100 |
|---|---|---|
| committer | Gerd Hoffmann | 2017-02-02 15:58:23 +0100 |
| commit | 62d4c6bd5263bb8413a06c80144fc678df6dfb64 (patch) | |
| tree | aa25a3b95608e0f825c312751b11bf7039080b2d | |
| parent | cirrus: fix blit address mask handling (diff) | |
| download | qemu-62d4c6bd5263bb8413a06c80144fc678df6dfb64.tar.gz qemu-62d4c6bd5263bb8413a06c80144fc678df6dfb64.tar.xz qemu-62d4c6bd5263bb8413a06c80144fc678df6dfb64.zip | |
cirrus: fix oob access issue (CVE-2017-2615)
When doing bitblt copy in backward mode, we should minus the
blt width first just like the adding in the forward mode. This
can avoid the oob access of the front of vga's vram.
Signed-off-by: Li Qiang <liqiang6-s@360.cn>
{ kraxel: with backward blits (negative pitch) addr is the topmost
address, so check it as-is against vram size ]
Cc: qemu-stable@nongnu.org
Cc: P J P <ppandit@redhat.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Wolfgang Bumiller <w.bumiller@proxmox.com>
Fixes: d3532a0db02296e687711b8cdc7791924efccea0 (CVE-2014-8106)
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-id: 1485938101-26602-1-git-send-email-kraxel@redhat.com
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
| -rw-r--r-- | hw/display/cirrus_vga.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/hw/display/cirrus_vga.c b/hw/display/cirrus_vga.c index 7db6409dc5..16f27e8ac5 100644 --- a/hw/display/cirrus_vga.c +++ b/hw/display/cirrus_vga.c @@ -274,10 +274,9 @@ static bool blit_region_is_unsafe(struct CirrusVGAState *s, { if (pitch < 0) { int64_t min = addr - + ((int64_t)s->cirrus_blt_height-1) * pitch; - int32_t max = addr - + s->cirrus_blt_width; - if (min < 0 || max > s->vga.vram_size) { + + ((int64_t)s->cirrus_blt_height - 1) * pitch + - s->cirrus_blt_width; + if (min < -1 || addr >= s->vga.vram_size) { return true; } } else { |