Fix CVE-2020-29074 (insecure permissions on a shared memory)

The file is already stored in a git tree.

sources

@@ -1,2 +1 @@
 a372ec4fe8211221547b1c108cf56e4c  x11vnc-0.9.13.tar.gz
-6ace0b145956b6c7d65290d88e92e5f7  x11vnc-0.9.8-disableRpath.patch

x11vnc-0.9.13-scan-limit-access-to-shared-memory-segments-to-curre.patch

@@ -0,0 +1,32 @@
+From a43cac178bc5722169b25c70335038f03ca7034d Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Gu=C3=A9nal=20DAVALAN?= <guenal.davalan@uca.fr>
+Date: Wed, 18 Nov 2020 08:40:45 +0100
+Subject: [PATCH] scan: limit access to shared memory segments to current user
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Petr Písař: Ported to 0.9.13 from upstream
+69eeb9f7baa14ca03b16c9de821f9876def7a36a commit.
+
+Signed-off-by: Petr Písař <ppisar@redhat.com>
+---
+ x11vnc/scan.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/x11vnc/scan.c b/x11vnc/scan.c
+index 2b03666..dfc5599 100644
+--- a/x11vnc/scan.c
++++ b/x11vnc/scan.c
+@@ -320,7 +320,7 @@ static int shm_create(XShmSegmentInfo *shm, XImage **ximg_ptr, int w, int h,
+ 
+ #if LIBVNCSERVER_HAVE_XSHM
+ 	shm->shmid = shmget(IPC_PRIVATE,
+-	    xim->bytes_per_line * xim->height, IPC_CREAT | 0777);
++	    xim->bytes_per_line * xim->height, IPC_CREAT | 0600);
+ 
+ 	if (shm->shmid == -1) {
+ 		rfbErr("shmget(%s) failed.\n", name);
+-- 
+2.26.2
+

x11vnc.spec

@@ -2,7 +2,7 @@ Summary:		VNC server for the current X11 session
 Summary(ru):	VNC-сервер для текущей сессии X11
 Name:		x11vnc
 Version:		0.9.13
-Release:		11%{?dist}
+Release:		12%{?dist}
 License:		GPLv2
 Group:		User Interface/X
 URL:			http://www.karlrunge.com/x11vnc/
@@ -28,6 +28,9 @@ Requires:		Xvfb
 
 # Fedora don't want hardcoded rpaths.
 Patch1:		x11vnc-0.9.8-disableRpath.patch
+# Fix CVE-2020-29074 (insecure permissions on a shared memory), bug #1933604,
+# in upstream after 0.9.16
+Patch2:		x11vnc-0.9.13-scan-limit-access-to-shared-memory-segments-to-curre.patch
 
 # Package intended to EL-5 too, so we still need define BuildRoot
 BuildRoot:	%{_tmppath}/%{name}-%{version}-%{release}-root-%(%{__id_u} -n)
@@ -87,6 +90,7 @@ Java-клиенты для использования совместно с %{na
 %prep
 %setup -q
 %patch1 -p0 -b .rpath
+%patch2 -p1
 
 # fix source perms for the -debuginfo package rpmlint warnings
 find -name "*.c" -o -name "*.h" -exec %{__chmod} 0644 {} \;
@@ -155,6 +159,9 @@ popd
 %endif
 
 %changelog
+* Mon Mar 01 2021 Petr Pisar <ppisar@redhat.com> - 0.9.13-12
+- Fix CVE-2020-29074 (insecure permissions on a shared memory) (bug #1933604)
+
 * Sat Dec 28 2013 Rex Dieter <rdieter@fedoraproject.org> 0.9.13-11
 - enable avahi support and xfixes/xinerama/xrandr extensions... for real (#864947)