ghostscript: Fix 3 CVEs

It was discovered that the ghostscript /invalidaccess checks fail under
certain conditions. An attacker could possibly exploit this to bypass
the -dSAFER protection and, for example, execute arbitrary shell commands
via a specially crafted PostScript document.

It was found that the superexec operator was available in the internal
dictionary in ghostscript before 9.27. A specially crafted PostScript
file could use this flaw in order to, for example, have access to the
file system outside of the constrains imposed by -dSAFER.

It was found that the forceput operator could be extracted from the
DefineResource method in ghostscript before 9.27. A specially crafted
PostScript file could use this flaw in order to, for example, have
access to the file system outside of the constrains imposed by -dSAFER.

References:
https://nvd.nist.gov/vuln/detail/CVE-2019-6116
https://www.openwall.com/lists/oss-security/2019/01/23/5
https://nvd.nist.gov/vuln/detail/CVE-2019-3835
https://nvd.nist.gov/vuln/detail/CVE-2019-3838

Upstream patches:
http://git.ghostscript.com/?p=ghostpdl.git;a=commitdiff;h=13b0a36
http://git.ghostscript.com/?p=ghostpdl.git;a=commitdiff;h=2db98f9
http://git.ghostscript.com/?p=ghostpdl.git;a=commitdiff;h=99f1309
http://git.ghostscript.com/?p=ghostpdl.git;a=commitdiff;h=59d8f4d
http://git.ghostscript.com/?p=ghostpdl.git;a=commitdiff;h=2768d1a
http://git.ghostscript.com/?p=ghostpdl.git;a=commitdiff;h=49c8092
http://git.ghostscript.com/?p=ghostpdl.git;a=commitdiff;h=2ff600a
http://git.ghostscript.com/?p=ghostpdl.git;a=commitdiff;h=779664d
http://git.ghostscript.com/?p=ghostpdl.git;a=commitdiff;h=e8acf6d
http://git.ghostscript.com/?p=ghostpdl.git;a=commitdiff;h=2055917
http://git.ghostscript.com/?p=ghostpdl.git;a=commitdiff;h=d683d1e
http://git.ghostscript.com/?p=ghostpdl.git;a=commitdiff;h=ed9fcd9
http://git.ghostscript.com/?p=ghostpdl.git;a=commitdiff;h=a82601e

(From OE-Core rev: 12e140dfdac8456772223c816e37bd869419bb18)

Signed-off-by: Ovidiu Panait <ovidiu.panait@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 99 insertions, 0 deletions

diff --git a/meta/recipes-extended/ghostscript/ghostscript/CVE-2019-3835-0001.patch b/meta/recipes-extended/ghostscript/ghostscript/CVE-2019-3835-0001.patch
new file mode 100644
index 0000000000..30ce04a7b1
--- /dev/null
+++ b/meta/recipes-extended/ghostscript/ghostscript/CVE-2019-3835-0001.patch
@@ -0,0 +1,99 @@
+From ad3ad6b389653722507e588c5cb34d8731e49e89 Mon Sep 17 00:00:00 2001
+From: Chris Liddell <chris.liddell@artifex.com>
+Date: Mon, 26 Nov 2018 18:01:25 +0000
+Subject: [PATCH] Have gs_cet.ps run from gs_init.ps
+
+Previously gs_cet.ps was run on the command line, to set up the interpreter
+state so our output more closely matches the example output for the QL CET
+tests.
+
+Allow a -dCETMODE command line switch, which will cause gs_init.ps to run the
+file directly.
+
+This works better for gpdl as it means the changes are made in the intial
+interpreter state, rather than after initialisation is complete.
+
+This also means adding a definition of the default procedure for black
+generation and under color removal (rather it being defined in-line in
+.setdefaultbgucr
+
+Also, add a check so gs_cet.ps only runs once - if we try to run it a second
+time, we'll just skip over the file, flushing through to the end.
+
+CVE: CVE-2019-3835
+Upstream-Status: Backport [git://git.ghostscript.com/ghostpdl.git]
+
+Signed-off-by: Ovidiu Panait <ovidiu.panait@windriver.com>
+---
+ Resource/Init/gs_cet.ps  | 11 ++++++++++-
+ Resource/Init/gs_init.ps | 13 ++++++++++++-
+ 2 files changed, 22 insertions(+), 2 deletions(-)
+
+diff --git a/Resource/Init/gs_cet.ps b/Resource/Init/gs_cet.ps
+index d3e1686..75534bb 100644
+--- a/Resource/Init/gs_cet.ps
++++ b/Resource/Init/gs_cet.ps
+@@ -1,6 +1,11 @@
+ %!PS
+ % Set defaults for Ghostscript to match Adobe CPSI behaviour for CET
+ 
++systemdict /product get (PhotoPRINT SE 5.0v2) readonly eq
++{
++  (%END GS_CET) .skipeof
++} if
++
+ % do this in the server level so it is persistent across jobs
+ //true 0 startjob not {
+   (*** Warning: CET startup is not in server default) = flush
+@@ -25,7 +30,9 @@ currentglobal //true setglobal
+ 
+ /UNROLLFORMS true def
+ 
+-{ } bind dup
++(%.defaultbgrucrproc) cvn { } bind def
++
++(%.defaultbgrucrproc) cvn load dup
+ setblackgeneration
+ setundercolorremoval
+ 0 array cvx readonly dup dup dup setcolortransfer
+@@ -109,3 +116,5 @@ userdict /.smoothness currentsmoothness put
+ % end of slightly nasty hack to give consistent cluster results
+ 
+ //false 0 startjob pop         % re-enter encapsulated mode
++
++%END GS_CET
+diff --git a/Resource/Init/gs_init.ps b/Resource/Init/gs_init.ps
+index 45bebf4..e6b9cd2 100644
+--- a/Resource/Init/gs_init.ps
++++ b/Resource/Init/gs_init.ps
+@@ -1538,10 +1538,18 @@ setpacking
+   % any-part-of-pixel rule.
+   0.5 .setfilladjust
+ } bind def
++
+ % Set the default screen and BG/UCR.
++% We define the proc here, rather than inline in .setdefaultbgucr
++% for the benefit of gs_cet.ps so jobs that do anything that causes
++% .setdefaultbgucr to be called will still get the redefined proc
++% in gs_cet.ps
++(%.defaultbgrucrproc) cvn { pop 0 } def
++
+ /.setdefaultbgucr {
+   systemdict /setblackgeneration known {
+-    { pop 0 } dup setblackgeneration setundercolorremoval
++    (%.defaultbgrucrproc) cvn load dup
++    setblackgeneration setundercolorremoval
+   } if
+ } bind def
+ /.useloresscreen {     % - .useloresscreen <bool>
+@@ -2491,4 +2499,7 @@ WRITESYSTEMDICT {
+ % be 'true' in some cases.
+ userdict /AGM_preserve_spots //false put
+ 
++systemdict /CETMODE .knownget
++{ { (gs_cet.ps) runlibfile } if } if
++
+ % The interpreter will run the initial procedure (start).
+-- 
+2.18.1
+