user/libice: patch for CVE-2017-2626

1 files changed, 142 insertions, 0 deletions

diff --git a/user/libice/CVE-2017-2626.patch b/user/libice/CVE-2017-2626.patch
new file mode 100644
index 000000000..ea2d8835b
--- /dev/null
+++ b/user/libice/CVE-2017-2626.patch
@@ -0,0 +1,142 @@
+From ff5e59f32255913bb1cdf51441b98c9107ae165b Mon Sep 17 00:00:00 2001
+From: Benjamin Tissoires <benjamin.tissoires@gmail.com>
+Date: Tue, 4 Apr 2017 19:12:53 +0200
+Subject: Use getentropy() if arc4random_buf() is not available
+
+This allows to fix CVE-2017-2626 on Linux platforms without pulling in
+libbsd.
+The libc getentropy() is available since glibc 2.25 but also on OpenBSD.
+For Linux, we need at least a v3.17 kernel. If the recommended
+arc4random_buf() function is not available, emulate it by first trying
+to use getentropy() on a supported glibc and kernel. If the call fails,
+fall back to the current (partly vulnerable) code.
+
+Signed-off-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>
+Reviewed-by: Mark Kettenis <kettenis@openbsd.org>
+Reviewed-by: Alan Coopersmith <alan.coopersmith@oracle.com>
+Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
+---
+ configure.ac  |  2 +-
+ src/iceauth.c | 65 ++++++++++++++++++++++++++++++++++++++++++-----------------
+ 2 files changed, 47 insertions(+), 20 deletions(-)
+
+diff --git a/configure.ac b/configure.ac
+index 458882a..c971ab6 100644
+--- a/configure.ac
++++ b/configure.ac
+@@ -38,7 +38,7 @@ AC_DEFINE(ICE_t, 1, [Xtrans transport type])
+ 
+ # Checks for library functions.
+ AC_CHECK_LIB([bsd], [arc4random_buf])
+-AC_CHECK_FUNCS([asprintf arc4random_buf])
++AC_CHECK_FUNCS([asprintf arc4random_buf getentropy])
+ 
+ # Allow checking code with lint, sparse, etc.
+ XORG_WITH_LINT
+diff --git a/src/iceauth.c b/src/iceauth.c
+index ed31683..de4785b 100644
+--- a/src/iceauth.c
++++ b/src/iceauth.c
+@@ -44,31 +44,19 @@ Author: Ralph Mor, X Consortium
+ 
+ static int was_called_state;
+ 
+-/*
+- * MIT-MAGIC-COOKIE-1 is a sample authentication method implemented by
+- * the SI.  It is not part of standard ICElib.
+- */
++#ifndef HAVE_ARC4RANDOM_BUF
+ 
+-
+-char *
+-IceGenerateMagicCookie (
++static void
++emulate_getrandom_buf (
++	char *auth,
+ 	int len
+ )
+ {
+-    char    *auth;
+-#ifndef HAVE_ARC4RANDOM_BUF
+     long    ldata[2];
+     int	    seed;
+     int	    value;
+     int	    i;
+-#endif
+ 
+-    if ((auth = malloc (len + 1)) == NULL)
+-	return (NULL);
+-
+-#ifdef HAVE_ARC4RANDOM_BUF
+-    arc4random_buf(auth, len);
+-#else
+ #ifdef ITIMER_REAL
+     {
+ 	struct timeval  now;
+@@ -76,13 +64,13 @@ IceGenerateMagicCookie (
+ 	ldata[0] = now.tv_sec;
+ 	ldata[1] = now.tv_usec;
+     }
+-#else
++#else /* ITIMER_REAL */
+     {
+ 	long    time ();
+ 	ldata[0] = time ((long *) 0);
+ 	ldata[1] = getpid ();
+     }
+-#endif
++#endif /* ITIMER_REAL */
+     seed = (ldata[0]) + (ldata[1] << 16);
+     srand (seed);
+     for (i = 0; i < len; i++)
+@@ -90,7 +78,46 @@ IceGenerateMagicCookie (
+ 	value = rand ();
+ 	auth[i] = value & 0xff;
+     }
+-#endif
++}
++
++static void
++arc4random_buf (
++	char *auth,
++	int len
++)
++{
++    int	    ret;
++
++#if HAVE_GETENTROPY
++    /* weak emulation of arc4random through the entropy libc */
++    ret = getentropy (auth, len);
++    if (ret == 0)
++	return;
++#endif /* HAVE_GETENTROPY */
++
++    emulate_getrandom_buf (auth, len);
++}
++
++#endif /* !defined(HAVE_ARC4RANDOM_BUF) */
++
++/*
++ * MIT-MAGIC-COOKIE-1 is a sample authentication method implemented by
++ * the SI.  It is not part of standard ICElib.
++ */
++
++
++char *
++IceGenerateMagicCookie (
++	int len
++)
++{
++    char    *auth;
++
++    if ((auth = malloc (len + 1)) == NULL)
++	return (NULL);
++
++    arc4random_buf (auth, len);
++
+     auth[len] = '\0';
+     return (auth);
+ }
+-- 
+cgit v1.1
+