Subject: [PATCH 2/3] Revert "cirrus: allow zero source pitch in pattern fill rops"

From: Gerd Hoffmann <[email-masked]>
Date: Fri, 10 Feb 2017 08:30:14 +0100

RH-Author: Gerd Hoffmann <[email-masked]>
Message-id: <[email-masked]>
Patchwork-id: 73774
O-Subject: [virt-devel] [RHEL-7.4 qemu-kvm PATCH 2/3] Revert "cirrus: allow zero source pitch in pattern fill rops"
Bugzilla: 1420493
CVE: CVE-2017-2620/20170221
RH-Acked-by: Paolo Bonzini <[email-masked]>
RH-Acked-by: Dr. David Alan Gilbert <[email-masked]>
RH-Acked-by: Laurent Vivier <[email-masked]>

This reverts commit 5858dd1801883309bdd208d72ddb81c4e9fee30c.

Signed-off-by: Miroslav Rezanina <[email-masked]>

Conflicts:
	hw/display/cirrus_vga.c

Cc: Wolfgang Bumiller <[email-masked]>
Cc: Dr. David Alan Gilbert <[email-masked]>
Signed-off-by: Gerd Hoffmann <[email-masked]>

Upstream: WIP (https://patchwork.ozlabs.org/patch/726074/)
---
 hw/display/cirrus_vga.c | 26 ++++++++------------------
 1 file changed, 8 insertions(+), 18 deletions(-)

diff --git a/hw/display/cirrus_vga.c b/hw/display/cirrus_vga.c
index d055ffb..93aa596 100644
--- a/hw/display/cirrus_vga.c
+++ b/hw/display/cirrus_vga.c
@@ -272,6 +272,9 @@ static void cirrus_update_memory_access(CirrusVGAState *s);
 static bool blit_region_is_unsafe(struct CirrusVGAState *s,
                                   int32_t pitch, int32_t addr)
 {
+    if (!pitch) {
+        return true;
+    }
     if (pitch < 0) {
         int64_t min = addr
             + ((int64_t)s->cirrus_blt_height - 1) * pitch
@@ -290,11 +293,8 @@ static bool blit_region_is_unsafe(struct CirrusVGAState *s,
     return false;
 }
 
-static bool blit_is_unsafe(struct CirrusVGAState *s, bool dst_only,
-                           bool zero_src_pitch_ok)
+static bool blit_is_unsafe(struct CirrusVGAState *s, bool dst_only)
 {
-    int32_t check_pitch;
-
     /* should be the case, see cirrus_bitblt_start */
     assert(s->cirrus_blt_width > 0);
     assert(s->cirrus_blt_height > 0);
@@ -303,10 +303,6 @@ static bool blit_is_unsafe(struct CirrusVGAState *s, bool dst_only,
         return true;
     }
 
-    if (!s->cirrus_blt_dstpitch) {
-        return true;
-    }
-
     if (blit_region_is_unsafe(s, s->cirrus_blt_dstpitch,
                               s->cirrus_blt_dstaddr)) {
         return true;
@@ -314,13 +310,7 @@ static bool blit_is_unsafe(struct CirrusVGAState *s, bool dst_only,
     if (dst_only) {
         return false;
     }
-
-    check_pitch = s->cirrus_blt_srcpitch;
-    if (!zero_src_pitch_ok && !check_pitch) {
-        check_pitch = s->cirrus_blt_width;
-    }
-
-    if (blit_region_is_unsafe(s, check_pitch,
+    if (blit_region_is_unsafe(s, s->cirrus_blt_srcpitch,
                               s->cirrus_blt_srcaddr)) {
         return true;
     }
@@ -715,7 +705,7 @@ static int cirrus_bitblt_common_patterncopy(CirrusVGAState *s, bool videosrc)
         src = s->cirrus_bltbuf;
     }
 
-    if (blit_is_unsafe(s, true, true)) {
+    if (blit_is_unsafe(s, true)) {
         return 0;
     }
 
@@ -734,7 +724,7 @@ static int cirrus_bitblt_solidfill(CirrusVGAState *s, int blt_rop)
 {
     cirrus_fill_t rop_func;
 
-    if (blit_is_unsafe(s, true, true)) {
+    if (blit_is_unsafe(s, true)) {
         return 0;
     }
     rop_func = cirrus_fill[rop_to_index[blt_rop]][s->cirrus_blt_pixelwidth - 1];
@@ -834,7 +824,7 @@ static int cirrus_do_copy(CirrusVGAState *s, int dst, int src, int w, int h)
 
 static int cirrus_bitblt_videotovideo_copy(CirrusVGAState * s)
 {
-    if (blit_is_unsafe(s, false, false))
+    if (blit_is_unsafe(s, false))
         return 0;
 
     return cirrus_do_copy(s, s->cirrus_blt_dstaddr - s->vga.start_addr,
-- 
1.8.3.1