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From be86d2ff2f0f0ea0e365707f3be0fa0c9e7315ee Mon Sep 17 00:00:00 2001
From: Ray Johnston <ray.johnston@artifex.com>
Date: Mon, 18 Feb 2019 12:11:45 -0800
Subject: [PATCH 1/2] Bug 700599: Issue an error message if an ExtGstate is not
 found.

Previously, this was silently ignored. Only issue a single warning,
and respect PDFSTOPONERROR to prevent continuing with potentially
incorrect output.

Note that tests_private/pdf/uploads/bug696410.pdf also now gets this
error message (ExtGState" instead of ExtGState in object 10).
---
 Resource/Init/pdf_draw.ps | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/Resource/Init/pdf_draw.ps b/Resource/Init/pdf_draw.ps
index 1add3f7..6a2773a 100644
--- a/Resource/Init/pdf_draw.ps
+++ b/Resource/Init/pdf_draw.ps
@@ -494,7 +494,16 @@ end
     dup {
       oforce exch gsparamdict exch .knownget { exec } { pop } ifelse
     } forall pop
-  } if
+  } {
+    //pdfdict /.gs_warning_issued known not {
+      (\n   **** Error 'gs' ignored -- ExtGState missing from Resources.\n)
+      pdfformaterror
+      (        Output may be incorrect.\n) pdfformaterror
+      //pdfdict /.gs_warning_issued //true .forceput
+      PDFSTOPONERROR { /gs /undefined signalerror } if
+    } if
+  }
+  ifelse
 } bind executeonly def
 
 % ------ Transparency support ------ %
-- 
2.20.1


From cd1b1cacadac2479e291efe611979bdc1b3bdb19 Mon Sep 17 00:00:00 2001
From: Ken Sharp <ken.sharp@artifex.com>
Date: Wed, 21 Aug 2019 10:10:51 +0100
Subject: [PATCH 2/2] PDF interpreter - review .forceput security

Bug #701450 "Safer Mode Bypass by .forceput Exposure in .pdfexectoken"

By abusing the error handler it was possible to get the PDFDEBUG portion
of .pdfexectoken, which uses .forceput left readable.

Add an executeonly appropriately to make sure that clause isn't readable
no mstter what.

Review all the uses of .forceput searching for similar cases, add
executeonly as required to secure those. All cases in the PostScript
support files seem to be covered already.
---
 Resource/Init/pdf_base.ps |  2 +-
 Resource/Init/pdf_draw.ps | 14 +++++++-------
 Resource/Init/pdf_font.ps | 23 ++++++++++++-----------
 Resource/Init/pdf_main.ps |  6 +++---
 Resource/Init/pdf_ops.ps  | 11 ++++++-----
 5 files changed, 29 insertions(+), 27 deletions(-)

diff --git a/Resource/Init/pdf_base.ps b/Resource/Init/pdf_base.ps
index d3c3a5f..5dabe4d 100644
--- a/Resource/Init/pdf_base.ps
+++ b/Resource/Init/pdf_base.ps
@@ -154,7 +154,7 @@ currentdict /num-chars-dict .undef
     {
       dup ==only () = flush
     } ifelse % PDFSTEP
-  } if % PDFDEBUG
+  } executeonly if % PDFDEBUG
   2 copy .knownget {
     exch pop exch pop exch pop exec
   } {
diff --git a/Resource/Init/pdf_draw.ps b/Resource/Init/pdf_draw.ps
index 6a2773a..068ba7c 100644
--- a/Resource/Init/pdf_draw.ps
+++ b/Resource/Init/pdf_draw.ps
@@ -501,8 +501,8 @@ end
       (        Output may be incorrect.\n) pdfformaterror
       //pdfdict /.gs_warning_issued //true .forceput
       PDFSTOPONERROR { /gs /undefined signalerror } if
-    } if
-  }
+    } executeonly if
+  } executeonly
   ifelse
 } bind executeonly def
 
@@ -1127,7 +1127,7 @@ currentdict end readonly def
           .setglobal
           pdfformaterror
         } executeonly ifelse
-      }
+      } executeonly
       {
         currentglobal //pdfdict gcheck .setglobal
         //pdfdict /.Qqwarning_issued //true .forceput
@@ -1135,8 +1135,8 @@ currentdict end readonly def
         pdfformaterror
       } executeonly ifelse
       end
-    } ifelse
-  } loop
+    } executeonly ifelse
+  } executeonly loop
   {
     (\n   **** Error: File has unbalanced q/Q operators \(too many q's\)\n               Output may be incorrect.\n)
     //pdfdict /.Qqwarning_issued .knownget
@@ -1150,14 +1150,14 @@ currentdict end readonly def
         .setglobal
         pdfformaterror
       } executeonly ifelse
-    }
+    } executeonly
     {
       currentglobal //pdfdict gcheck .setglobal
       //pdfdict /.Qqwarning_issued //true .forceput
       .setglobal
       pdfformaterror
     } executeonly ifelse
-  } if
+  } executeonly if
   pop
 
   % restore pdfemptycount
diff --git a/Resource/Init/pdf_font.ps b/Resource/Init/pdf_font.ps
index 8b8fef8..86b1870 100644
--- a/Resource/Init/pdf_font.ps
+++ b/Resource/Init/pdf_font.ps
@@ -677,7 +677,7 @@ currentdict end readonly def
                 currentglobal 2 index dup gcheck setglobal
                 /FontInfo 5 dict dup 5 1 roll .forceput
                 setglobal
-              } if
+              } executeonly if
               dup /GlyphNames2Unicode .knownget not {
                 //true                        % No existing G2U, make one
               } {
@@ -701,9 +701,9 @@ currentdict end readonly def
         } if
         PDFDEBUG {
           (.processToUnicode end) =
-        } if
-      } if
-    } stopped
+        } executeonly if
+      } executeonly if
+    } executeonly stopped
     {
       .dstackdepth 1 countdictstack 1 sub
       {pop end} for
@@ -1225,19 +1225,20 @@ currentdict /eexec_pdf_param_dict .undef
                 //pdfdict /.Qqwarning_issued //true .forceput
               } executeonly if
               Q
-            } repeat
+            } executeonly repeat
             Q
-          } PDFfile fileposition 2 .execn % Keep pdfcount valid.
+          } executeonly PDFfile fileposition 2 .execn % Keep pdfcount valid.
           PDFfile exch setfileposition
-        } ifelse
-      } {
+        } executeonly ifelse
+      } executeonly
+      {
         % PDF Type 3 fonts don't use .notdef
         % d1 implementation adjusts the width as needed
         0 0 0 0 0 0
         pdfopdict /d1 get exec
       } ifelse
       end end
-    } bdef
+    } executeonly bdef
     dup currentdict Encoding .processToUnicode
     currentdict end .completefont exch pop
 } bind executeonly odef
@@ -2022,9 +2023,9 @@ currentdict /CMap_read_dict undef
           (Will continue, but content may be missing.) = flush
         } ifelse
       } if
-    } if
+    } executeonly if
     /findresource cvx /undefined signalerror
-  } loop
+  } executeonly loop
 } bind executeonly odef
 
 /buildCIDType0 {	% <CIDFontType0-font-resource> buildCIDType0 <font>
diff --git a/Resource/Init/pdf_main.ps b/Resource/Init/pdf_main.ps
index e44288e..ecde3d4 100644
--- a/Resource/Init/pdf_main.ps
+++ b/Resource/Init/pdf_main.ps
@@ -2696,15 +2696,15 @@ currentdict /PDF2PS_matrix_key undef
           .setglobal
           pdfformaterror
         } executeonly ifelse
-      }
+      } executeonly
       {
         currentglobal //pdfdict gcheck .setglobal
         //pdfdict /.Qqwarning_issued //true .forceput
         .setglobal
         pdfformaterror
       } executeonly ifelse
-    } if
-  } if
+    } executeonly if
+  } executeonly if
   pop
   count PDFexecstackcount sub { pop } repeat
   (after exec) VMDEBUG
diff --git a/Resource/Init/pdf_ops.ps b/Resource/Init/pdf_ops.ps
index c2e7461..12d5a66 100644
--- a/Resource/Init/pdf_ops.ps
+++ b/Resource/Init/pdf_ops.ps
@@ -186,14 +186,14 @@ currentdict /gput_always_allow .undef
         .setglobal
         pdfformaterror
       } executeonly ifelse
-    }
+    } executeonly
     {
       currentglobal //pdfdict gcheck .setglobal
       //pdfdict /.Qqwarning_issued //true .forceput
       .setglobal
       pdfformaterror
     } executeonly ifelse
-  } if
+  } executeonly if
 } bind executeonly odef
 
 % Save PDF gstate
@@ -440,11 +440,12 @@ currentdict /gput_always_allow .undef
   dup type /booleantype eq {
     .currentSMask type /dicttype eq {
       .currentSMask /Processed 2 index .forceput
+    } executeonly
+    {
+      .setSMask
+    }ifelse
   } executeonly
   {
-      .setSMask
-  }ifelse
-  }{
   .setSMask
   }ifelse
 
-- 
2.20.1