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authorH.J. Lu <hjl.tools@gmail.com>2017-07-11 07:44:01 -0700
committerH.J. Lu <hjl.tools@gmail.com>2017-07-11 07:44:14 -0700
commited421fca42fd9b4cab7c66e77894b8dd7ca57ed0 (patch)
treef1131793bd3340ada62e6d31434e1d8003eec2fd /debug
parent94070f86c0c849c71ed2e7e2189bb4d1f7411a17 (diff)
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Avoid backtrace from __stack_chk_fail [BZ #12189]
__stack_chk_fail is called on corrupted stack. Stack backtrace is very unreliable against corrupted stack. __libc_message is changed to accept enum __libc_message_action and call BEFORE_ABORT only if action includes do_backtrace. __fortify_fail_abort is added to avoid backtrace from __stack_chk_fail. [BZ #12189] * debug/Makefile (CFLAGS-tst-ssp-1.c): New. (tests): Add tst-ssp-1 if -fstack-protector works. * debug/fortify_fail.c: Include <stdbool.h>. (_fortify_fail_abort): New function. (__fortify_fail): Call _fortify_fail_abort. (__fortify_fail_abort): Add a hidden definition. * debug/stack_chk_fail.c: Include <stdbool.h>. (__stack_chk_fail): Call __fortify_fail_abort, instead of __fortify_fail. * debug/tst-ssp-1.c: New file. * include/stdio.h (__libc_message_action): New enum. (__libc_message): Replace int with enum __libc_message_action. (__fortify_fail_abort): New hidden prototype. * malloc/malloc.c (malloc_printerr): Update __libc_message calls. * sysdeps/posix/libc_fatal.c (__libc_message): Replace int with enum __libc_message_action. Call BEFORE_ABORT only if action includes do_backtrace. (__libc_fatal): Update __libc_message call.
Diffstat (limited to 'debug')
-rw-r--r--debug/Makefile6
-rw-r--r--debug/fortify_fail.c15
-rw-r--r--debug/stack_chk_fail.c3
-rw-r--r--debug/tst-ssp-1.c45
4 files changed, 66 insertions, 3 deletions
diff --git a/debug/Makefile b/debug/Makefile
index cd4975c..c6d7872 100644
--- a/debug/Makefile
+++ b/debug/Makefile
@@ -139,12 +139,18 @@ LDFLAGS-tst-backtrace4 = -rdynamic
LDFLAGS-tst-backtrace5 = -rdynamic
LDFLAGS-tst-backtrace6 = -rdynamic
+CFLAGS-tst-ssp-1.c = -fstack-protector
+
tests = backtrace-tst tst-longjmp_chk tst-chk1 tst-chk2 tst-chk3 \
tst-lfschk1 tst-lfschk2 tst-lfschk3 test-strcpy_chk test-stpcpy_chk \
tst-chk4 tst-chk5 tst-chk6 tst-lfschk4 tst-lfschk5 tst-lfschk6 \
tst-longjmp_chk2 tst-backtrace2 tst-backtrace3 tst-backtrace4 \
tst-backtrace5 tst-backtrace6
+ifeq ($(have-ssp),yes)
+tests += tst-ssp-1
+endif
+
ifeq (,$(CXX))
tests-unsupported = tst-chk4 tst-chk5 tst-chk6 \
tst-lfschk4 tst-lfschk5 tst-lfschk6
diff --git a/debug/fortify_fail.c b/debug/fortify_fail.c
index a31977a..c90d384 100644
--- a/debug/fortify_fail.c
+++ b/debug/fortify_fail.c
@@ -17,17 +17,28 @@
#include <stdio.h>
#include <stdlib.h>
+#include <stdbool.h>
extern char **__libc_argv attribute_hidden;
void
__attribute__ ((noreturn)) internal_function
-__fortify_fail (const char *msg)
+__fortify_fail_abort (_Bool do_backtrace, const char *msg)
{
/* The loop is added only to keep gcc happy. */
while (1)
- __libc_message (2, "*** %s ***: %s terminated\n",
+ __libc_message (do_backtrace ? (do_abort | do_backtrace) : do_abort,
+ "*** %s ***: %s terminated\n",
msg, __libc_argv[0] ?: "<unknown>");
}
+
+void
+__attribute__ ((noreturn)) internal_function
+__fortify_fail (const char *msg)
+{
+ __fortify_fail_abort (true, msg);
+}
+
libc_hidden_def (__fortify_fail)
+libc_hidden_def (__fortify_fail_abort)
diff --git a/debug/stack_chk_fail.c b/debug/stack_chk_fail.c
index 4f73464..9ab9bc7 100644
--- a/debug/stack_chk_fail.c
+++ b/debug/stack_chk_fail.c
@@ -17,6 +17,7 @@
#include <stdio.h>
#include <stdlib.h>
+#include <stdbool.h>
extern char **__libc_argv attribute_hidden;
@@ -25,7 +26,7 @@ void
__attribute__ ((noreturn))
__stack_chk_fail (void)
{
- __fortify_fail ("stack smashing detected");
+ __fortify_fail_abort (false, "stack smashing detected");
}
strong_alias (__stack_chk_fail, __stack_chk_fail_local)
diff --git a/debug/tst-ssp-1.c b/debug/tst-ssp-1.c
new file mode 100644
index 0000000..52c67e2
--- /dev/null
+++ b/debug/tst-ssp-1.c
@@ -0,0 +1,45 @@
+/* Verify that __stack_chk_fail won't segfault.
+ Copyright (C) 2017 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/>. */
+
+/* Based on gcc.dg/ssp-1.c from GCC testsuite. */
+
+#include <signal.h>
+
+static void
+__attribute__ ((noinline, noclone))
+test (char *foo)
+{
+ int i;
+
+ /* smash stack */
+ for (i = 0; i <= 400; i++)
+ foo[i] = 42;
+}
+
+static int
+do_test (void)
+{
+ char foo[30];
+
+ test (foo);
+
+ return 1; /* fail */
+}
+
+#define EXPECTED_SIGNAL SIGABRT
+#include <support/test-driver.c>