#

# CVE-2013-4788 The pointer guard used for pointer mangling was not

# initialized for static applications resulting in the security feature

# being disabled. The pointer guard is now correctly initialized to a

# random value for static applications. Existing static applications need

# to be recompiled to take advantage of the fix (bug 15754).

#

# Not yet upstream.

#

diff --git a/csu/libc-start.c b/csu/libc-start.c

index e5da3ef..c898d06 100644

--- a/csu/libc-start.c

+++ b/csu/libc-start.c

@@ -37,6 +37,12 @@ extern void __pthread_initialize_minimal (void);

    in thread local area.  */

 uintptr_t __stack_chk_guard attribute_relro;

 # endif

+# ifndef  THREAD_SET_POINTER_GUARD

+/* Only exported for architectures that don't store the pointer guard

+   value in thread local area.  */

+uintptr_t __pointer_chk_guard_local

+	attribute_relro attribute_hidden __attribute__ ((nocommon));

+# endif

 #endif

 #ifdef HAVE_PTR_NTHREADS

@@ -195,6 +201,16 @@ LIBC_START_MAIN (int (*main) (int, char **, char ** MAIN_AUXVEC_DECL),

 # else

   __stack_chk_guard = stack_chk_guard;

 # endif

+

+  /* Set up the pointer guard value.  */

+  uintptr_t pointer_chk_guard = _dl_setup_pointer_guard (_dl_random,

+							 stack_chk_guard);

+# ifdef THREAD_SET_POINTER_GUARD

+  THREAD_SET_POINTER_GUARD (pointer_chk_guard);

+# else

+  __pointer_chk_guard_local = pointer_chk_guard;

+# endif

+

 #endif

   /* Register the destructor of the dynamic linker if there is any.  */

diff --git a/elf/Makefile b/elf/Makefile

index aaa9534..cb8da93 100644

--- a/elf/Makefile

+++ b/elf/Makefile

@@ -121,7 +121,8 @@ endif

 tests = tst-tls1 tst-tls2 tst-tls9 tst-leaks1 \

 	tst-array1 tst-array2 tst-array3 tst-array4 tst-array5

 tests-static = tst-tls1-static tst-tls2-static tst-stackguard1-static \

-	       tst-leaks1-static tst-array1-static tst-array5-static

+	       tst-leaks1-static tst-array1-static tst-array5-static \

+	       tst-ptrguard1-static

 ifeq (yes,$(build-shared))

 tests-static += tst-tls9-static

 tst-tls9-static-ENV = \

@@ -145,7 +146,8 @@ tests += loadtest restest1 preloadtest loadfail multiload origtest resolvfail \

 	 tst-audit1 tst-audit2 tst-audit8 \

 	 tst-stackguard1 tst-addr1 tst-thrlock \

 	 tst-unique1 tst-unique2 tst-unique3 tst-unique4 \

-	 tst-initorder tst-initorder2 tst-relsort1 tst-null-argv

+	 tst-initorder tst-initorder2 tst-relsort1 tst-null-argv \

+	 tst-ptrguard1

 #	 reldep9

 test-srcs = tst-pathopt

 selinux-enabled := $(shell cat /selinux/enforce 2> /dev/null)

@@ -1016,6 +1018,9 @@ LDFLAGS-order2mod2.so = $(no-as-needed)

 tst-stackguard1-ARGS = --command "$(host-test-program-cmd) --child"

 tst-stackguard1-static-ARGS = --command "$(objpfx)tst-stackguard1-static --child"

+tst-ptrguard1-ARGS = --command "$(host-test-program-cmd) --child"

+tst-ptrguard1-static-ARGS = --command "$(objpfx)tst-ptrguard1-static --child"

+

 $(objpfx)tst-leaks1: $(libdl)

 $(objpfx)tst-leaks1-mem: $(objpfx)tst-leaks1.out

 	$(common-objpfx)malloc/mtrace $(objpfx)tst-leaks1.mtrace > $@

diff --git a/elf/tst-ptrguard1-static.c b/elf/tst-ptrguard1-static.c

new file mode 100644

index 0000000..7aff3b7

--- /dev/null

+++ b/elf/tst-ptrguard1-static.c

@@ -0,0 +1 @@

+#include "tst-ptrguard1.c"

diff --git a/elf/tst-ptrguard1.c b/elf/tst-ptrguard1.c

new file mode 100644

index 0000000..c344a04

--- /dev/null

+++ b/elf/tst-ptrguard1.c

@@ -0,0 +1,202 @@

+/* Copyright (C) 2013 Free Software Foundation, Inc.

+   This file is part of the GNU C Library.

+

+   The GNU C Library is free software; you can redistribute it and/or

+   modify it under the terms of the GNU Lesser General Public

+   License as published by the Free Software Foundation; either

+   version 2.1 of the License, or (at your option) any later version.

+

+   The GNU C Library is distributed in the hope that it will be useful,

+   but WITHOUT ANY WARRANTY; without even the implied warranty of

+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

+   Lesser General Public License for more details.

+

+   You should have received a copy of the GNU Lesser General Public

+   License along with the GNU C Library; if not, see

+   <http://www.gnu.org/licenses/>.  */

+

+#include <errno.h>

+#include <stdbool.h>

+#include <stdio.h>

+#include <stdlib.h>

+#include <string.h>

+#include <sys/wait.h>

+#include <stackguard-macros.h>

+#include <tls.h>

+#include <unistd.h>

+

+#ifndef POINTER_CHK_GUARD

+extern uintptr_t __pointer_chk_guard;

+# define POINTER_CHK_GUARD __pointer_chk_guard

+#endif

+

+static const char *command;

+static bool child;

+static uintptr_t ptr_chk_guard_copy;

+static bool ptr_chk_guard_copy_set;

+static int fds[2];

+

+static void __attribute__ ((constructor))

+con (void)

+{

+  ptr_chk_guard_copy = POINTER_CHK_GUARD;

+  ptr_chk_guard_copy_set = true;

+}

+

+static int

+uintptr_t_cmp (const void *a, const void *b)

+{

+  if (*(uintptr_t *) a < *(uintptr_t *) b)

+    return 1;

+  if (*(uintptr_t *) a > *(uintptr_t *) b)

+    return -1;

+  return 0;

+}

+

+static int

+do_test (void)

+{

+  if (!ptr_chk_guard_copy_set)

+    {

+      puts ("constructor has not been run");

+      return 1;

+    }

+

+  if (ptr_chk_guard_copy != POINTER_CHK_GUARD)

+    {

+      puts ("POINTER_CHK_GUARD changed between constructor and do_test");

+      return 1;

+    }

+

+  if (child)

+    {

+      write (2, &ptr_chk_guard_copy, sizeof (ptr_chk_guard_copy));

+      return 0;

+    }

+

+  if (command == NULL)

+    {

+      puts ("missing --command or --child argument");

+      return 1;

+    }

+

+#define N 16

+  uintptr_t child_ptr_chk_guards[N + 1];

+  child_ptr_chk_guards[N] = ptr_chk_guard_copy;

+  int i;

+  for (i = 0; i < N; ++i)

+    {

+      if (pipe (fds) < 0)

+	{

+	  printf ("couldn't create pipe: %m\n");

+	  return 1;

+	}

+

+      pid_t pid = fork ();

+      if (pid < 0)

+	{

+	  printf ("fork failed: %m\n");

+	  return 1;

+	}

+

+      if (!pid)

+	{

+	  if (ptr_chk_guard_copy != POINTER_CHK_GUARD)

+	    {

+	      puts ("POINTER_CHK_GUARD changed after fork");

+	      exit (1);

+	    }

+

+	  close (fds[0]);

+	  close (2);

+	  dup2 (fds[1], 2);

+	  close (fds[1]);

+

+	  system (command);

+	  exit (0);

+	}

+

+      close (fds[1]);

+

+      if (TEMP_FAILURE_RETRY (read (fds[0], &child_ptr_chk_guards[i],

+				    sizeof (uintptr_t))) != sizeof (uintptr_t))

+	{

+	  puts ("could not read ptr_chk_guard value from child");

+	  return 1;

+	}

+

+      close (fds[0]);

+

+      pid_t termpid;

+      int status;

+      termpid = TEMP_FAILURE_RETRY (waitpid (pid, &status, 0));

+      if (termpid == -1)

+	{

+	  printf ("waitpid failed: %m\n");

+	  return 1;

+	}

+      else if (termpid != pid)

+	{

+	  printf ("waitpid returned %ld != %ld\n",

+		  (long int) termpid, (long int) pid);

+	  return 1;

+	}

+      else if (!WIFEXITED (status) || WEXITSTATUS (status))

+	{

+	  puts ("child hasn't exited with exit status 0");

+	  return 1;

+	}

+    }

+

+  qsort (child_ptr_chk_guards, N + 1, sizeof (uintptr_t), uintptr_t_cmp);

+

+  /* The default pointer guard is the same as the default stack guard.

+     They are only set to default if dl_random is NULL.  */

+  uintptr_t default_guard = 0;

+  unsigned char *p = (unsigned char *) &default_guard;

+  p[sizeof (uintptr_t) - 1] = 255;

+  p[sizeof (uintptr_t) - 2] = '\n';

+  p[0] = 0;

+

+  /* Test if the pointer guard canaries are either randomized,

+     or equal to the default pointer guard value.

+     Even with randomized pointer guards it might happen

+     that the random number generator generates the same

+     values, but if that happens in more than half from

+     the 16 runs, something is very wrong.  */

+  int ndifferences = 0;

+  int ndefaults = 0;

+  for (i = 0; i < N; ++i)

+    {

+      if (child_ptr_chk_guards[i] != child_ptr_chk_guards[i+1])

+	ndifferences++;

+      else if (child_ptr_chk_guards[i] == default_guard)

+	ndefaults++;

+    }

+

+  printf ("differences %d defaults %d\n", ndifferences, ndefaults);

+

+  if (ndifferences < N / 2 && ndefaults < N / 2)

+    {

+      puts ("pointer guard values are not randomized enough");

+      puts ("nor equal to the default value");

+      return 1;

+    }

+

+  return 0;

+}

+

+#define OPT_COMMAND	10000

+#define OPT_CHILD	10001

+#define CMDLINE_OPTIONS	\

+  { "command", required_argument, NULL, OPT_COMMAND },  \

+  { "child", no_argument, NULL, OPT_CHILD },

+#define CMDLINE_PROCESS	\

+  case OPT_COMMAND:	\

+    command = optarg;	\

+    break;		\

+  case OPT_CHILD:	\

+    child = true;	\

+    break;

+#define TEST_FUNCTION do_test ()

+#include "../test-skeleton.c"

diff --git a/ports/sysdeps/ia64/stackguard-macros.h b/ports/sysdeps/ia64/stackguard-macros.h

index dc683c2..3907293 100644

--- a/ports/sysdeps/ia64/stackguard-macros.h

+++ b/ports/sysdeps/ia64/stackguard-macros.h

@@ -2,3 +2,6 @@

 #define STACK_CHK_GUARD \

   ({ uintptr_t x; asm ("adds %0 = -8, r13;; ld8 %0 = [%0]" : "=r" (x)); x; })

+

+#define POINTER_CHK_GUARD \

+  ({ uintptr_t x; asm ("adds %0 = -16, r13;; ld8 %0 = [%0]" : "=r" (x)); x; })

diff --git a/ports/sysdeps/tile/stackguard-macros.h b/ports/sysdeps/tile/stackguard-macros.h

index 589ea2b..f2e041b 100644

--- a/ports/sysdeps/tile/stackguard-macros.h

+++ b/ports/sysdeps/tile/stackguard-macros.h

@@ -4,11 +4,17 @@

 # if __WORDSIZE == 64

 #  define STACK_CHK_GUARD \

   ({ uintptr_t x; asm ("addi %0, tp, -16; ld %0, %0" : "=r" (x)); x; })

+#  define POINTER_CHK_GUARD \

+  ({ uintptr_t x; asm ("addi %0, tp, -24; ld %0, %0" : "=r" (x)); x; })

 # else

 #  define STACK_CHK_GUARD \

   ({ uintptr_t x; asm ("addi %0, tp, -8; ld4s %0, %0" : "=r" (x)); x; })

+#  define POINTER_CHK_GUARD \

+  ({ uintptr_t x; asm ("addi %0, tp, -12; ld4s %0, %0" : "=r" (x)); x; })

 # endif

 #else

 # define STACK_CHK_GUARD \

   ({ uintptr_t x; asm ("addi %0, tp, -8; lw %0, %0" : "=r" (x)); x; })

+# define POINTER_CHK_GUARD \

+  ({ uintptr_t x; asm ("addi %0, tp, -12; lw %0, %0" : "=r" (x)); x; })

 #endif

diff --git a/sysdeps/generic/stackguard-macros.h b/sysdeps/generic/stackguard-macros.h

index ababf65..77408c6 100644

--- a/sysdeps/generic/stackguard-macros.h

+++ b/sysdeps/generic/stackguard-macros.h

@@ -2,3 +2,6 @@

 extern uintptr_t __stack_chk_guard;

 #define STACK_CHK_GUARD __stack_chk_guard

+

+extern uintptr_t __pointer_chk_guard_local;

+#define POINTER_CHK_GUARD __pointer_chk_guard_local

diff --git a/sysdeps/i386/stackguard-macros.h b/sysdeps/i386/stackguard-macros.h

index 8c31e19..0397629 100644

--- a/sysdeps/i386/stackguard-macros.h

+++ b/sysdeps/i386/stackguard-macros.h

@@ -2,3 +2,11 @@

 #define STACK_CHK_GUARD \

   ({ uintptr_t x; asm ("movl %%gs:0x14, %0" : "=r" (x)); x; })

+

+#define POINTER_CHK_GUARD \

+  ({							\

+     uintptr_t x;					\

+     asm ("movl %%gs:%c1, %0" : "=r" (x)		\

+	  : "i" (offsetof (tcbhead_t, pointer_guard)));	\

+     x;							\

+   })

diff --git a/sysdeps/powerpc/powerpc32/stackguard-macros.h b/sysdeps/powerpc/powerpc32/stackguard-macros.h

index 839f6a4..b3d0af8 100644

--- a/sysdeps/powerpc/powerpc32/stackguard-macros.h

+++ b/sysdeps/powerpc/powerpc32/stackguard-macros.h

@@ -2,3 +2,13 @@

 #define STACK_CHK_GUARD \

   ({ uintptr_t x; asm ("lwz %0,-28680(2)" : "=r" (x)); x; })

+

+#define POINTER_CHK_GUARD \

+  ({												\

+     uintptr_t x;										\

+     asm ("lwz %0,%1(2)"									\

+	  : "=r" (x)										\

+	  : "i" (offsetof (tcbhead_t, pointer_guard) - TLS_TCB_OFFSET - sizeof (tcbhead_t))	\

+         );											\

+     x;												\

+   })

diff --git a/sysdeps/powerpc/powerpc64/stackguard-macros.h b/sysdeps/powerpc/powerpc64/stackguard-macros.h

index 9da879c..4620f96 100644

--- a/sysdeps/powerpc/powerpc64/stackguard-macros.h

+++ b/sysdeps/powerpc/powerpc64/stackguard-macros.h

@@ -2,3 +2,13 @@

 #define STACK_CHK_GUARD \

   ({ uintptr_t x; asm ("ld %0,-28688(13)" : "=r" (x)); x; })

+

+#define POINTER_CHK_GUARD \

+  ({												\

+     uintptr_t x;										\

+     asm ("ld %0,%1(2)"										\

+	  : "=r" (x)										\

+	  : "i" (offsetof (tcbhead_t, pointer_guard) - TLS_TCB_OFFSET - sizeof (tcbhead_t))	\

+         );											\

+     x;												\

+   })

diff --git a/sysdeps/s390/s390-32/stackguard-macros.h b/sysdeps/s390/s390-32/stackguard-macros.h

index b74c579..449e8d4 100644

--- a/sysdeps/s390/s390-32/stackguard-macros.h

+++ b/sysdeps/s390/s390-32/stackguard-macros.h

@@ -2,3 +2,14 @@

 #define STACK_CHK_GUARD \

   ({ uintptr_t x; asm ("ear %0,%%a0; l %0,0x14(%0)" : "=a" (x)); x; })

+

+/* On s390/s390x there is no unique pointer guard, instead we use the

+   same value as the stack guard.  */

+#define POINTER_CHK_GUARD \

+  ({							\

+     uintptr_t x;					\

+     asm ("ear %0,%%a0; l %0,%1(%0)"			\

+	  : "=a" (x)					\

+	  : "i" (offsetof (tcbhead_t, stack_guard)));	\

+     x;							\

+   })

diff --git a/sysdeps/s390/s390-64/stackguard-macros.h b/sysdeps/s390/s390-64/stackguard-macros.h

index 0cebb5f..c8270fb 100644

--- a/sysdeps/s390/s390-64/stackguard-macros.h

+++ b/sysdeps/s390/s390-64/stackguard-macros.h

@@ -2,3 +2,17 @@

 #define STACK_CHK_GUARD \

   ({ uintptr_t x; asm ("ear %0,%%a0; sllg %0,%0,32; ear %0,%%a1; lg %0,0x28(%0)" : "=a" (x)); x; })

+

+/* On s390/s390x there is no unique pointer guard, instead we use the

+   same value as the stack guard.  */

+#define POINTER_CHK_GUARD \

+  ({							\

+     uintptr_t x;					\

+     asm ("ear %0,%%a0;"				\

+	  "sllg %0,%0,32;"				\

+	  "ear %0,%%a1;"				\

+	  "lg %0,%1(%0)"				\

+	 : "=a" (x)					\

+	 : "i" (offsetof (tcbhead_t, stack_guard)));	\

+     x;							\

+   })

diff --git a/sysdeps/sparc/sparc32/stackguard-macros.h b/sysdeps/sparc/sparc32/stackguard-macros.h

index c0b02b0..1eef0f1 100644

--- a/sysdeps/sparc/sparc32/stackguard-macros.h

+++ b/sysdeps/sparc/sparc32/stackguard-macros.h

@@ -2,3 +2,6 @@

 #define STACK_CHK_GUARD \

   ({ uintptr_t x; asm ("ld [%%g7+0x14], %0" : "=r" (x)); x; })

+

+#define POINTER_CHK_GUARD \

+  ({ uintptr_t x; asm ("ld [%%g7+0x18], %0" : "=r" (x)); x; })

diff --git a/sysdeps/sparc/sparc64/stackguard-macros.h b/sysdeps/sparc/sparc64/stackguard-macros.h

index 80f0635..cc0c12c 100644

--- a/sysdeps/sparc/sparc64/stackguard-macros.h

+++ b/sysdeps/sparc/sparc64/stackguard-macros.h

@@ -2,3 +2,6 @@

 #define STACK_CHK_GUARD \

   ({ uintptr_t x; asm ("ldx [%%g7+0x28], %0" : "=r" (x)); x; })

+

+#define POINTER_CHK_GUARD \

+  ({ uintptr_t x; asm ("ldx [%%g7+0x30], %0" : "=r" (x)); x; })

diff --git a/sysdeps/x86_64/stackguard-macros.h b/sysdeps/x86_64/stackguard-macros.h

index d7fedb3..1948800 100644

--- a/sysdeps/x86_64/stackguard-macros.h

+++ b/sysdeps/x86_64/stackguard-macros.h

@@ -4,3 +4,8 @@

   ({ uintptr_t x;						\

      asm ("mov %%fs:%c1, %0" : "=r" (x)				\

 	  : "i" (offsetof (tcbhead_t, stack_guard))); x; })

+

+#define POINTER_CHK_GUARD \

+  ({ uintptr_t x;						\

+     asm ("mov %%fs:%c1, %0" : "=r" (x)				\

+	  : "i" (offsetof (tcbhead_t, pointer_guard))); x; })

diff --git a/elf/Makefile b/elf/Makefile

index cb8da93..27d249b 100644

--- a/elf/Makefile

+++ b/elf/Makefile

@@ -1019,6 +1019,9 @@ tst-stackguard1-ARGS = --command "$(host-test-program-cmd) --child"

 tst-stackguard1-static-ARGS = --command "$(objpfx)tst-stackguard1-static --child"

 tst-ptrguard1-ARGS = --command "$(host-test-program-cmd) --child"

+# When built statically, the pointer guard interface uses

+# __pointer_chk_guard_local.

+CFLAGS-tst-ptrguard1-static.c = -DPTRGUARD_LOCAL

 tst-ptrguard1-static-ARGS = --command "$(objpfx)tst-ptrguard1-static --child"

 $(objpfx)tst-leaks1: $(libdl)

diff --git a/sysdeps/generic/stackguard-macros.h b/sysdeps/generic/stackguard-macros.h

index 4fa3d96..b4a6b23 100644

--- a/sysdeps/generic/stackguard-macros.h

+++ b/sysdeps/generic/stackguard-macros.h

@@ -3,5 +3,10 @@

 extern uintptr_t __stack_chk_guard;

 #define STACK_CHK_GUARD __stack_chk_guard

+#ifdef PTRGUARD_LOCAL

 extern uintptr_t __pointer_chk_guard_local;

-#define POINTER_CHK_GUARD __pointer_chk_guard_local

+# define POINTER_CHK_GUARD __pointer_chk_guard_local

+#else

+extern uintptr_t __pointer_chk_guard;

+# define POINTER_CHK_GUARD __pointer_chk_guard

+#endif