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From: Gerd Hoffmann <kraxel@redhat.com>
Date: Mon, 30 May 2016 09:09:19 +0200
Subject: [PATCH] vmsvga: add more fifo checks
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Make sure all fifo ptrs are within range.

Fixes: CVE-2016-4454
Cc: qemu-stable@nongnu.org
Cc: P J P <ppandit@redhat.com>
Reported-by: 李强 <liqiang6-s@360.cn>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-id: 1464592161-18348-3-git-send-email-kraxel@redhat.com
(cherry picked from commit c2e3c54d3960bc53bfa3a5ce7ea7a050b9be267e)
---
 hw/display/vmware_vga.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/hw/display/vmware_vga.c b/hw/display/vmware_vga.c
index b12128a..0329d9f 100644
--- a/hw/display/vmware_vga.c
+++ b/hw/display/vmware_vga.c
@@ -561,7 +561,10 @@ static inline int vmsvga_fifo_length(struct vmsvga_state_s *s)
     if (CMD(min) < (uint8_t *) s->cmd->fifo - (uint8_t *) s->fifo) {
         return 0;
     }
-    if (CMD(max) > SVGA_FIFO_SIZE) {
+    if (CMD(max) > SVGA_FIFO_SIZE ||
+        CMD(min) >= SVGA_FIFO_SIZE ||
+        CMD(stop) >= SVGA_FIFO_SIZE ||
+        CMD(next_cmd) >= SVGA_FIFO_SIZE) {
         return 0;
     }
     if (CMD(max) < CMD(min) + 10 * 1024) {