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authorFlorian Weimer <fweimer@redhat.com>2016-04-25 14:10:26 +0200
committerFlorian Weimer <fweimer@redhat.com>2016-04-25 14:10:26 +0200
commitfdcf1c9480342d9f5fc2d23f142d621bcb4d00a4 (patch)
tree1678f802177bb5f37a058e857a43da5363ab5d8e /stdio-common
parenta5507dfa60a8b92ba52dadabea88e2b5d91da655 (diff)
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vfprintf: Fix memory with large width and precision [BZ #19931]
Free a previously allocated work buffer if it is not large enough.
Diffstat (limited to 'stdio-common')
-rw-r--r--stdio-common/Makefile14
-rw-r--r--stdio-common/tst-vfprintf-width-prec.c107
-rw-r--r--stdio-common/vfprintf.c5
3 files changed, 121 insertions, 5 deletions
diff --git a/stdio-common/Makefile b/stdio-common/Makefile
index cc79d34..6c597c1 100644
--- a/stdio-common/Makefile
+++ b/stdio-common/Makefile
@@ -58,16 +58,18 @@ tests := tstscanf test_rdwr test-popen tstgetln test-fseek \
scanf16 scanf17 tst-setvbuf1 tst-grouping bug23 bug24 \
bug-vfprintf-nargs tst-long-dbl-fphex tst-fphex-wide tst-sprintf3 \
bug25 tst-printf-round bug23-2 bug23-3 bug23-4 bug26 tst-fmemopen3 \
- tst-printf-bz18872
+ tst-printf-bz18872 tst-vfprintf-width-prec
test-srcs = tst-unbputc tst-printf
ifeq ($(run-built-tests),yes)
tests-special += $(objpfx)tst-unbputc.out $(objpfx)tst-printf.out \
$(objpfx)tst-printf-bz18872-mem.out \
- $(objpfx)tst-setvbuf1-cmp.out
+ $(objpfx)tst-setvbuf1-cmp.out \
+ $(objpfx)tst-vfprintf-width-prec-mem.out
generated += tst-printf-bz18872.c tst-printf-bz18872.mtrace \
- tst-printf-bz18872-mem.out
+ tst-printf-bz18872-mem.out \
+ tst-vfprintf-width-prec.mtrace tst-vfprintf-width-prec-mem.out
endif
include ../Rules
@@ -86,6 +88,8 @@ $(objpfx)tst-swprintf.out: $(gen-locales)
endif
tst-printf-bz18872-ENV = MALLOC_TRACE=$(objpfx)tst-printf-bz18872.mtrace
+tst-vfprintf-width-prec-ENV = \
+ MALLOC_TRACE=$(objpfx)tst-vfprintf-width-prec.mtrace
$(objpfx)tst-unbputc.out: tst-unbputc.sh $(objpfx)tst-unbputc
$(SHELL) $< $(common-objpfx) '$(test-program-prefix)'; \
@@ -100,8 +104,8 @@ $(objpfx)tst-printf.out: tst-printf.sh $(objpfx)tst-printf
$(objpfx)tst-printf-bz18872.c: tst-printf-bz18872.sh
rm -f $@ && $(BASH) $^ > $@.new && mv $@.new $@
-$(objpfx)tst-printf-bz18872-mem.out: $(objpfx)tst-printf-bz18872.out
- $(common-objpfx)malloc/mtrace $(objpfx)tst-printf-bz18872.mtrace > $@; \
+$(objpfx)tst-%-mem.out: $(objpfx)tst-%.out
+ $(common-objpfx)malloc/mtrace $(objpfx)tst-$*.mtrace > $@; \
$(evaluate-test)
CFLAGS-vfprintf.c = -Wno-uninitialized
diff --git a/stdio-common/tst-vfprintf-width-prec.c b/stdio-common/tst-vfprintf-width-prec.c
new file mode 100644
index 0000000..2892741
--- /dev/null
+++ b/stdio-common/tst-vfprintf-width-prec.c
@@ -0,0 +1,107 @@
+/* Test for memory leak with large width and precision.
+ Copyright (C) 1991-2016 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 <mcheck.h>
+#include <stdio.h>
+#include <sys/resource.h>
+#include <wchar.h>
+
+static int
+do_test (void)
+{
+ mtrace ();
+
+ int ret;
+ {
+ char *result;
+ ret = asprintf (&result, "%133000.133001x", 17);
+ if (ret < 0)
+ {
+ printf ("error: asprintf: %m\n");
+ return 1;
+ }
+ free (result);
+ }
+ {
+ wchar_t *result = calloc (ret + 1, sizeof (wchar_t));
+ if (result == NULL)
+ {
+ printf ("error: calloc (%d, %zu): %m", ret + 1, sizeof (wchar_t));
+ return 1;
+ }
+
+ ret = swprintf (result, ret + 1, L"%133000.133001x", 17);
+ if (ret < 0)
+ {
+ printf ("error: swprintf: %d (%m)\n", ret);
+ return 1;
+ }
+ free (result);
+ }
+
+ /* Limit the size of the process, so that the second allocation will
+ fail. */
+ {
+ struct rlimit limit;
+ if (getrlimit (RLIMIT_AS, &limit) != 0)
+ {
+ printf ("getrlimit (RLIMIT_AS) failed: %m\n");
+ return 1;
+ }
+ long target = 200 * 1024 * 1024;
+ if (limit.rlim_cur == RLIM_INFINITY || limit.rlim_cur > target)
+ {
+ limit.rlim_cur = target;
+ if (setrlimit (RLIMIT_AS, &limit) != 0)
+ {
+ printf ("setrlimit (RLIMIT_AS) failed: %m\n");
+ return 1;
+ }
+ }
+ }
+
+ {
+ char *result;
+ ret = asprintf (&result, "%133000.999999999x", 17);
+ if (ret >= 0)
+ {
+ printf ("error: asprintf: incorrect result %d\n", ret);
+ return 1;
+ }
+ }
+ {
+ wchar_t result[100];
+ if (result == NULL)
+ {
+ printf ("error: calloc (%d, %zu): %m", ret + 1, sizeof (wchar_t));
+ return 1;
+ }
+
+ ret = swprintf (result, 100, L"%133000.999999999x", 17);
+ if (ret >= 0)
+ {
+ printf ("error: swprintf: incorrect result %d\n", ret);
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"
diff --git a/stdio-common/vfprintf.c b/stdio-common/vfprintf.c
index 6829d4d..f24020a 100644
--- a/stdio-common/vfprintf.c
+++ b/stdio-common/vfprintf.c
@@ -1564,6 +1564,11 @@ vfprintf (FILE *s, const CHAR_T *format, va_list ap)
prec = 0;
if (prec > width && prec > WORK_BUFFER_SIZE - 32)
{
+ /* Deallocate any previously allocated buffer because it is
+ too small. */
+ if (__glibc_unlikely (workstart != NULL))
+ free (workstart);
+ workstart = NULL;
if (__glibc_unlikely (prec >= INT_MAX / sizeof (CHAR_T) - 32))
{
__set_errno (EOVERFLOW);