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authorCarlos O'Donell <carlos@redhat.com>2013-09-23 00:52:09 -0400
committerCarlos O'Donell <carlos@redhat.com>2013-09-23 00:52:09 -0400
commitc61b4d41c9647a54a329aa021341c0eb032b793e (patch)
treec4a665c232a7d37786a6f3b5e3f56d0ae11480e8 /sysdeps/s390/s390-64
parent58a96064d193317236b740998e134b652d3d62ad (diff)
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BZ #15754: 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.

The test tst-ptrguard1-static and tst-ptrguard1 add regression
coverage to ensure the pointer guards are sufficiently random
and initialized to a default value.
Diffstat (limited to 'sysdeps/s390/s390-64')
-rw-r--r--sysdeps/s390/s390-64/stackguard-macros.h14
1 files changed, 14 insertions, 0 deletions
diff --git a/sysdeps/s390/s390-64/stackguard-macros.h b/sysdeps/s390/s390-64/stackguard-macros.h
index 0cebb5f022..c8270fbe79 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;							\
+   })