Fix hardcoded /tmp paths in testing (bug 13888)

Message ID alpine.DEB.2.20.1806221611080.23994@digraph.polyomino.org.uk
State New, archived
Headers

Commit Message

Joseph Myers June 22, 2018, 4:17 p.m. UTC
  As noted in bug 13888, and as I noted previously in
<https://sourceware.org/ml/libc-alpha/2000-10/msg00111.html>, various
tests used hardcoded paths in /tmp, so posing issues for simultaneous
test runs from different build directories.

This patch fixes such uses of hardcoded file names to put them in the
build directory instead (in the case of stdio-common/bug5 the file
names are changed as well, to avoid a conflict with the name bug5.out
also used for the automatic test output redirection).  It also fixes
test-installation.pl likewise (that was using filenames with $$ in
them rather than strictly hardcoded names, but that's still not good
practice for temporary file naming).

Note that my list of files changed is not identical to that in bug
13888.  I added tst-spawn3.c and test-installation.pl, and removed
some tests that seem to me (now) to create temporary files securely
(simply using /tmp is not itself a problem if the temporary files are
handled properly with mkstemp; I haven't checked whether those tests
used to do things insecurely).  conformtest is not changed because the
makefiles always pass a --tmpdir option so the /tmp default is
irrelevant, and for the same reason there is no actual problem with
nptl/tst-umask1.c because again the makefiles always override the
default.

nptl/sockperf.c is ignored because there is no code to run it;
probably that file should actually be removed.

Some tests use the mktemp function, but I think they all use it in a
way that *is* secure (for generating names for directories / sockets /
fifos / symlinks, where the operation using the name will not follow
symlinks and so there is no potential for a symlink attack on the
account running the testsuite).

Some tests use the tmpnam function to generate temporary file names.
This is in principle insecure, but not addressed by this patch (I
consider it a separate issue from the fully hardcoded paths).

Tested for x86_64.

2018-06-22  Joseph Myers  <joseph@codesourcery.com>

	[BZ #13888]
	* posix/Makefile (CFLAGS-tst-spawn3.c): New variable.
	* posix/tst-spawn3.c (do_test): Put tst-spwan3.pid in OBJPFX, not
	/tmp.
	* scripts/test-installation.pl: Put temporary files in build
	directory, not /tmp.
	* stdio-common/Makefile (CFLAGS-bug3.c): New variable.
	(CFLAGS-bug4.c): Likewise.
	(CFLAGS-bug5.c): Likewise.
	(CFLAGS-test-fseek.c): Likewise.
	(CFLAGS-test-popen.c): Likewise.
	(CFLAGS-test_rdwr.c): Likewise.
	* stdio-common/bug3.c (main): Put temporary file in OBJPFX, not
	/tmp.
	* stdio-common/bug4.c (main): Likewise.
	* stdio-common/bug5.c (main): Likewise.
	* stdio-common/test-fseek.c (TESTFILE): Likewise.
	* stdio-common/test-popen.c (do_test): Likewise.
	* stdio-common/test_rdwr.c (main): Likewise.
  

Comments

Joseph Myers June 26, 2018, 8:40 p.m. UTC | #1
Ping.  This patch 
<https://sourceware.org/ml/libc-alpha/2018-06/msg00710.html> is pending 
review.
  
Adhemerval Zanella June 26, 2018, 8:57 p.m. UTC | #2
On 22/06/2018 13:17, Joseph Myers wrote:
> As noted in bug 13888, and as I noted previously in
> <https://sourceware.org/ml/libc-alpha/2000-10/msg00111.html>, various
> tests used hardcoded paths in /tmp, so posing issues for simultaneous
> test runs from different build directories.
> 
> This patch fixes such uses of hardcoded file names to put them in the
> build directory instead (in the case of stdio-common/bug5 the file
> names are changed as well, to avoid a conflict with the name bug5.out
> also used for the automatic test output redirection).  It also fixes
> test-installation.pl likewise (that was using filenames with $$ in
> them rather than strictly hardcoded names, but that's still not good
> practice for temporary file naming).
> 
> Note that my list of files changed is not identical to that in bug
> 13888.  I added tst-spawn3.c and test-installation.pl, and removed
> some tests that seem to me (now) to create temporary files securely
> (simply using /tmp is not itself a problem if the temporary files are
> handled properly with mkstemp; I haven't checked whether those tests
> used to do things insecurely).  conformtest is not changed because the
> makefiles always pass a --tmpdir option so the /tmp default is
> irrelevant, and for the same reason there is no actual problem with
> nptl/tst-umask1.c because again the makefiles always override the
> default.
> 
> nptl/sockperf.c is ignored because there is no code to run it;
> probably that file should actually be removed.
> 
> Some tests use the mktemp function, but I think they all use it in a
> way that *is* secure (for generating names for directories / sockets /
> fifos / symlinks, where the operation using the name will not follow
> symlinks and so there is no potential for a symlink attack on the
> account running the testsuite).
> 
> Some tests use the tmpnam function to generate temporary file names.
> This is in principle insecure, but not addressed by this patch (I
> consider it a separate issue from the fully hardcoded paths).
> 
> Tested for x86_64.
> 
> 2018-06-22  Joseph Myers  <joseph@codesourcery.com>
> 
> 	[BZ #13888]
> 	* posix/Makefile (CFLAGS-tst-spawn3.c): New variable.
> 	* posix/tst-spawn3.c (do_test): Put tst-spwan3.pid in OBJPFX, not
> 	/tmp.
> 	* scripts/test-installation.pl: Put temporary files in build
> 	directory, not /tmp.
> 	* stdio-common/Makefile (CFLAGS-bug3.c): New variable.
> 	(CFLAGS-bug4.c): Likewise.
> 	(CFLAGS-bug5.c): Likewise.
> 	(CFLAGS-test-fseek.c): Likewise.
> 	(CFLAGS-test-popen.c): Likewise.
> 	(CFLAGS-test_rdwr.c): Likewise.
> 	* stdio-common/bug3.c (main): Put temporary file in OBJPFX, not
> 	/tmp.
> 	* stdio-common/bug4.c (main): Likewise.
> 	* stdio-common/bug5.c (main): Likewise.
> 	* stdio-common/test-fseek.c (TESTFILE): Likewise.
> 	* stdio-common/test-popen.c (do_test): Likewise.
> 	* stdio-common/test_rdwr.c (main): Likewise.

LGTM, thanks.

> 
> diff --git a/posix/Makefile b/posix/Makefile
> index 4a9a1b5..989e42e 100644
> --- a/posix/Makefile
> +++ b/posix/Makefile
> @@ -256,6 +256,7 @@ tst-pcre-ARGS = PCRE.tests
>  tst-boost-ARGS = BOOST.tests
>  bug-glob1-ARGS = "$(objpfx)"
>  tst-execvp3-ARGS = --test-dir=$(objpfx)
> +CFLAGS-tst-spawn3.c += -DOBJPFX=\"$(objpfx)\"
>  
>  testcases.h: TESTS TESTS2C.sed
>  	LC_ALL=C sed -f TESTS2C.sed < $< > $@T
> diff --git a/posix/tst-spawn3.c b/posix/tst-spawn3.c
> index dc6bed5..b60a783 100644
> --- a/posix/tst-spawn3.c
> +++ b/posix/tst-spawn3.c
> @@ -82,8 +82,8 @@ do_test (void)
>    if (posix_spawn_file_actions_init (&a) != 0)
>      FAIL_EXIT1 ("posix_spawn_file_actions_init");
>  
> -  /* Executes a /bin/sh echo $$ 2>&1 > /tmp/tst-spawn3.pid .  */
> -  const char pidfile[] = "/tmp/tst-spawn3.pid";
> +  /* Executes a /bin/sh echo $$ 2>&1 > ${objpfx}tst-spawn3.pid .  */
> +  const char pidfile[] = OBJPFX "tst-spawn3.pid";
>    if (posix_spawn_file_actions_addopen (&a, STDOUT_FILENO, pidfile, O_WRONLY |
>  					O_CREAT | O_TRUNC, 0644) != 0)
>      FAIL_EXIT1 ("posix_spawn_file_actions_addopen");
> diff --git a/scripts/test-installation.pl b/scripts/test-installation.pl
> index 067da47..b2e4ba7 100755
> --- a/scripts/test-installation.pl
> +++ b/scripts/test-installation.pl
> @@ -79,10 +79,12 @@ arglist: while (@ARGV) {
>  
>  # We expect none or one argument.
>  if ($#ARGV == -1) {
> +    $dir = ".";
>      $soversions="soversions.mk";
>      $config="config.make";
>  } elsif ($#ARGV == 0) {
>      if (-d $ARGV[0]) {
> +      $dir = $ARGV[0];
>        $soversions = "$ARGV[0]/soversions.mk";
>        $config = "$ARGV[0]/config.make";
>      } else {
> @@ -141,8 +143,8 @@ close SOVERSIONS;
>  # Create test program and link it against all
>  # shared libraries
>  
> -open PRG, ">/tmp/test-prg$$.c"
> -  or die ("Couldn't write test file /tmp/test-prg$$.c");
> +open PRG, ">$dir/test-prg$$.c"
> +  or die ("Couldn't write test file $dir/test-prg$$.c");
>  
>  print PRG '
>  #include <stdio.h>
> @@ -154,7 +156,7 @@ int main(void) {
>  ';
>  close PRG;
>  
> -open GCC, "$CC /tmp/test-prg$$.c $link_libs -o /tmp/test-prg$$ 2>&1 |"
> +open GCC, "$CC $dir/test-prg$$.c $link_libs -o $dir/test-prg$$ 2>&1 |"
>    or die ("Couldn't execute $CC!");
>  
>  while (<GCC>) {
> @@ -172,7 +174,7 @@ if ($?) {
>  $ok = 1;
>  %found = ();
>  
> -open LDD, "ldd /tmp/test-prg$$ |"
> +open LDD, "ldd $dir/test-prg$$ |"
>    or die ("Couldn't execute ldd");
>  while (<LDD>) {
>    if (/^\s*lib/) {
> @@ -212,8 +214,8 @@ foreach (keys %versions) {
>  &installation_problem unless $ok;
>  
>  # Finally execute the test program
> -system ("/tmp/test-prg$$") == 0
> +system ("$dir/test-prg$$") == 0
>    or die ("Execution of test program failed");
>  
>  # Clean up after ourselves
> -unlink ("/tmp/test-prg$$", "/tmp/test-prg$$.c");
> +unlink ("$dir/test-prg$$", "$dir/test-prg$$.c");
> diff --git a/stdio-common/Makefile b/stdio-common/Makefile
> index 4503837..738a3ce 100644
> --- a/stdio-common/Makefile
> +++ b/stdio-common/Makefile
> @@ -145,6 +145,13 @@ CFLAGS-scanf15.c += -I../libio -I../stdlib -I../wcsmbs -I../time -I../string \
>  CFLAGS-scanf17.c += -I../libio -I../stdlib -I../wcsmbs -I../time -I../string \
>  		   -I../wctype
>  
> +CFLAGS-bug3.c += -DOBJPFX=\"$(objpfx)\"
> +CFLAGS-bug4.c += -DOBJPFX=\"$(objpfx)\"
> +CFLAGS-bug5.c += -DOBJPFX=\"$(objpfx)\"
> +CFLAGS-test-fseek.c += -DOBJPFX=\"$(objpfx)\"
> +CFLAGS-test-popen.c += -DOBJPFX=\"$(objpfx)\"
> +CFLAGS-test_rdwr.c += -DOBJPFX=\"$(objpfx)\"
> +
>  # tst-gets.c tests a deprecated function.
>  CFLAGS-tst-gets.c += -Wno-deprecated-declarations
>  
> diff --git a/stdio-common/bug3.c b/stdio-common/bug3.c
> index 6b2ed6b..62a6cab 100644
> --- a/stdio-common/bug3.c
> +++ b/stdio-common/bug3.c
> @@ -6,7 +6,7 @@ main (void)
>  {
>    FILE *f;
>    int i;
> -  const char filename[] = "/tmp/bug3.test";
> +  const char filename[] = OBJPFX "bug3.test";
>  
>    f = fopen(filename, "w+");
>    for (i=0; i<9000; i++)
> diff --git a/stdio-common/bug4.c b/stdio-common/bug4.c
> index a037786..cf7fe11 100644
> --- a/stdio-common/bug4.c
> +++ b/stdio-common/bug4.c
> @@ -10,7 +10,7 @@ main (int argc, char *argv[])
>    FILE *f;
>    int i;
>    char buffer[31];
> -  const char filename[] = "/tmp/bug4.test";
> +  const char filename[] = OBJPFX "bug4.test";
>  
>    while ((i = getopt (argc, argv, "rw")) != -1)
>      switch (i)
> diff --git a/stdio-common/bug5.c b/stdio-common/bug5.c
> index f655845..7bfe9b2 100644
> --- a/stdio-common/bug5.c
> +++ b/stdio-common/bug5.c
> @@ -14,8 +14,8 @@ main (void)
>  {
>    FILE *in;
>    FILE *out;
> -  static char inname[] = "/tmp/bug5.in";
> -  static char outname[] = "/tmp/bug5.out";
> +  static char inname[] = OBJPFX "bug5test.in";
> +  static char outname[] = OBJPFX "bug5test.out";
>    char *printbuf;
>    size_t i;
>    int result;
> diff --git a/stdio-common/test-fseek.c b/stdio-common/test-fseek.c
> index c313911..17cd90b 100644
> --- a/stdio-common/test-fseek.c
> +++ b/stdio-common/test-fseek.c
> @@ -17,7 +17,7 @@
>  
>  #include <stdio.h>
>  
> -#define TESTFILE "/tmp/test.dat"
> +#define TESTFILE OBJPFX "test.dat"
>  
>  static int
>  do_test (void)
> diff --git a/stdio-common/test-popen.c b/stdio-common/test-popen.c
> index 6e98d3c..206f212 100644
> --- a/stdio-common/test-popen.c
> +++ b/stdio-common/test-popen.c
> @@ -59,7 +59,7 @@ do_test (void)
>       the perhaps incompatible new shared libraries.  */
>    unsetenv ("LD_LIBRARY_PATH");
>  
> -  output = popen ("/bin/cat >/tmp/tstpopen.tmp", "w");
> +  output = popen ("/bin/cat >" OBJPFX "tstpopen.tmp", "w");
>    if (output == NULL)
>      {
>        perror ("popen");
> @@ -69,10 +69,10 @@ do_test (void)
>    write_data (output);
>    wstatus = pclose (output);
>    printf ("writing pclose returned %d\n", wstatus);
> -  input = popen ("/bin/cat /tmp/tstpopen.tmp", "r");
> +  input = popen ("/bin/cat " OBJPFX "tstpopen.tmp", "r");
>    if (input == NULL)
>      {
> -      perror ("/tmp/tstpopen.tmp");
> +      perror (OBJPFX "tstpopen.tmp");
>        puts ("Test FAILED!");
>        exit (1);
>      }
> @@ -80,7 +80,7 @@ do_test (void)
>    rstatus = pclose (input);
>    printf ("reading pclose returned %d\n", rstatus);
>  
> -  remove ("/tmp/tstpopen.tmp");
> +  remove (OBJPFX "tstpopen.tmp");
>  
>    errno = 0;
>    output = popen ("/bin/cat", "m");
> diff --git a/stdio-common/test_rdwr.c b/stdio-common/test_rdwr.c
> index f471570..3489873 100644
> --- a/stdio-common/test_rdwr.c
> +++ b/stdio-common/test_rdwr.c
> @@ -38,7 +38,7 @@ main (int argc, char **argv)
>    else
>      name = *argv;
>  
> -  (void) sprintf (filename, "/tmp/%s.test", name);
> +  (void) sprintf (filename, OBJPFX "%s.test", name);
>  
>    f = fopen (filename, "w+");
>    if (f == NULL)
>
  
Florian Weimer June 26, 2018, 8:57 p.m. UTC | #3
* Joseph Myers:

> +CFLAGS-bug3.c += -DOBJPFX=\"$(objpfx)\"
> +CFLAGS-bug4.c += -DOBJPFX=\"$(objpfx)\"
> +CFLAGS-bug5.c += -DOBJPFX=\"$(objpfx)\"
> +CFLAGS-test-fseek.c += -DOBJPFX=\"$(objpfx)\"
> +CFLAGS-test-popen.c += -DOBJPFX=\"$(objpfx)\"
> +CFLAGS-test_rdwr.c += -DOBJPFX=\"$(objpfx)\"

There is some overlap here with DJ's test-in-container patch, which
also needs to find a test directory (although there it is
$(common-objpfx)).

Should we make this available in a more general way, perhaps as a
subdir-specific header file, or by changing the make rule for
compiling tests?
  
Joseph Myers June 26, 2018, 9:47 p.m. UTC | #4
On Tue, 26 Jun 2018, Florian Weimer wrote:

> * Joseph Myers:
> 
> > +CFLAGS-bug3.c += -DOBJPFX=\"$(objpfx)\"
> > +CFLAGS-bug4.c += -DOBJPFX=\"$(objpfx)\"
> > +CFLAGS-bug5.c += -DOBJPFX=\"$(objpfx)\"
> > +CFLAGS-test-fseek.c += -DOBJPFX=\"$(objpfx)\"
> > +CFLAGS-test-popen.c += -DOBJPFX=\"$(objpfx)\"
> > +CFLAGS-test_rdwr.c += -DOBJPFX=\"$(objpfx)\"
> 
> There is some overlap here with DJ's test-in-container patch, which
> also needs to find a test directory (although there it is
> $(common-objpfx)).
> 
> Should we make this available in a more general way, perhaps as a
> subdir-specific header file, or by changing the make rule for
> compiling tests?

Only a few tests need this at all.  (Even those tests may not strictly 
need it, in that other temporary file machinery could be used, but putting 
those files in objpfx was certainly the minimum incremental fix to the 
issue with those tests.)
  

Patch

diff --git a/posix/Makefile b/posix/Makefile
index 4a9a1b5..989e42e 100644
--- a/posix/Makefile
+++ b/posix/Makefile
@@ -256,6 +256,7 @@  tst-pcre-ARGS = PCRE.tests
 tst-boost-ARGS = BOOST.tests
 bug-glob1-ARGS = "$(objpfx)"
 tst-execvp3-ARGS = --test-dir=$(objpfx)
+CFLAGS-tst-spawn3.c += -DOBJPFX=\"$(objpfx)\"
 
 testcases.h: TESTS TESTS2C.sed
 	LC_ALL=C sed -f TESTS2C.sed < $< > $@T
diff --git a/posix/tst-spawn3.c b/posix/tst-spawn3.c
index dc6bed5..b60a783 100644
--- a/posix/tst-spawn3.c
+++ b/posix/tst-spawn3.c
@@ -82,8 +82,8 @@  do_test (void)
   if (posix_spawn_file_actions_init (&a) != 0)
     FAIL_EXIT1 ("posix_spawn_file_actions_init");
 
-  /* Executes a /bin/sh echo $$ 2>&1 > /tmp/tst-spawn3.pid .  */
-  const char pidfile[] = "/tmp/tst-spawn3.pid";
+  /* Executes a /bin/sh echo $$ 2>&1 > ${objpfx}tst-spawn3.pid .  */
+  const char pidfile[] = OBJPFX "tst-spawn3.pid";
   if (posix_spawn_file_actions_addopen (&a, STDOUT_FILENO, pidfile, O_WRONLY |
 					O_CREAT | O_TRUNC, 0644) != 0)
     FAIL_EXIT1 ("posix_spawn_file_actions_addopen");
diff --git a/scripts/test-installation.pl b/scripts/test-installation.pl
index 067da47..b2e4ba7 100755
--- a/scripts/test-installation.pl
+++ b/scripts/test-installation.pl
@@ -79,10 +79,12 @@  arglist: while (@ARGV) {
 
 # We expect none or one argument.
 if ($#ARGV == -1) {
+    $dir = ".";
     $soversions="soversions.mk";
     $config="config.make";
 } elsif ($#ARGV == 0) {
     if (-d $ARGV[0]) {
+      $dir = $ARGV[0];
       $soversions = "$ARGV[0]/soversions.mk";
       $config = "$ARGV[0]/config.make";
     } else {
@@ -141,8 +143,8 @@  close SOVERSIONS;
 # Create test program and link it against all
 # shared libraries
 
-open PRG, ">/tmp/test-prg$$.c"
-  or die ("Couldn't write test file /tmp/test-prg$$.c");
+open PRG, ">$dir/test-prg$$.c"
+  or die ("Couldn't write test file $dir/test-prg$$.c");
 
 print PRG '
 #include <stdio.h>
@@ -154,7 +156,7 @@  int main(void) {
 ';
 close PRG;
 
-open GCC, "$CC /tmp/test-prg$$.c $link_libs -o /tmp/test-prg$$ 2>&1 |"
+open GCC, "$CC $dir/test-prg$$.c $link_libs -o $dir/test-prg$$ 2>&1 |"
   or die ("Couldn't execute $CC!");
 
 while (<GCC>) {
@@ -172,7 +174,7 @@  if ($?) {
 $ok = 1;
 %found = ();
 
-open LDD, "ldd /tmp/test-prg$$ |"
+open LDD, "ldd $dir/test-prg$$ |"
   or die ("Couldn't execute ldd");
 while (<LDD>) {
   if (/^\s*lib/) {
@@ -212,8 +214,8 @@  foreach (keys %versions) {
 &installation_problem unless $ok;
 
 # Finally execute the test program
-system ("/tmp/test-prg$$") == 0
+system ("$dir/test-prg$$") == 0
   or die ("Execution of test program failed");
 
 # Clean up after ourselves
-unlink ("/tmp/test-prg$$", "/tmp/test-prg$$.c");
+unlink ("$dir/test-prg$$", "$dir/test-prg$$.c");
diff --git a/stdio-common/Makefile b/stdio-common/Makefile
index 4503837..738a3ce 100644
--- a/stdio-common/Makefile
+++ b/stdio-common/Makefile
@@ -145,6 +145,13 @@  CFLAGS-scanf15.c += -I../libio -I../stdlib -I../wcsmbs -I../time -I../string \
 CFLAGS-scanf17.c += -I../libio -I../stdlib -I../wcsmbs -I../time -I../string \
 		   -I../wctype
 
+CFLAGS-bug3.c += -DOBJPFX=\"$(objpfx)\"
+CFLAGS-bug4.c += -DOBJPFX=\"$(objpfx)\"
+CFLAGS-bug5.c += -DOBJPFX=\"$(objpfx)\"
+CFLAGS-test-fseek.c += -DOBJPFX=\"$(objpfx)\"
+CFLAGS-test-popen.c += -DOBJPFX=\"$(objpfx)\"
+CFLAGS-test_rdwr.c += -DOBJPFX=\"$(objpfx)\"
+
 # tst-gets.c tests a deprecated function.
 CFLAGS-tst-gets.c += -Wno-deprecated-declarations
 
diff --git a/stdio-common/bug3.c b/stdio-common/bug3.c
index 6b2ed6b..62a6cab 100644
--- a/stdio-common/bug3.c
+++ b/stdio-common/bug3.c
@@ -6,7 +6,7 @@  main (void)
 {
   FILE *f;
   int i;
-  const char filename[] = "/tmp/bug3.test";
+  const char filename[] = OBJPFX "bug3.test";
 
   f = fopen(filename, "w+");
   for (i=0; i<9000; i++)
diff --git a/stdio-common/bug4.c b/stdio-common/bug4.c
index a037786..cf7fe11 100644
--- a/stdio-common/bug4.c
+++ b/stdio-common/bug4.c
@@ -10,7 +10,7 @@  main (int argc, char *argv[])
   FILE *f;
   int i;
   char buffer[31];
-  const char filename[] = "/tmp/bug4.test";
+  const char filename[] = OBJPFX "bug4.test";
 
   while ((i = getopt (argc, argv, "rw")) != -1)
     switch (i)
diff --git a/stdio-common/bug5.c b/stdio-common/bug5.c
index f655845..7bfe9b2 100644
--- a/stdio-common/bug5.c
+++ b/stdio-common/bug5.c
@@ -14,8 +14,8 @@  main (void)
 {
   FILE *in;
   FILE *out;
-  static char inname[] = "/tmp/bug5.in";
-  static char outname[] = "/tmp/bug5.out";
+  static char inname[] = OBJPFX "bug5test.in";
+  static char outname[] = OBJPFX "bug5test.out";
   char *printbuf;
   size_t i;
   int result;
diff --git a/stdio-common/test-fseek.c b/stdio-common/test-fseek.c
index c313911..17cd90b 100644
--- a/stdio-common/test-fseek.c
+++ b/stdio-common/test-fseek.c
@@ -17,7 +17,7 @@ 
 
 #include <stdio.h>
 
-#define TESTFILE "/tmp/test.dat"
+#define TESTFILE OBJPFX "test.dat"
 
 static int
 do_test (void)
diff --git a/stdio-common/test-popen.c b/stdio-common/test-popen.c
index 6e98d3c..206f212 100644
--- a/stdio-common/test-popen.c
+++ b/stdio-common/test-popen.c
@@ -59,7 +59,7 @@  do_test (void)
      the perhaps incompatible new shared libraries.  */
   unsetenv ("LD_LIBRARY_PATH");
 
-  output = popen ("/bin/cat >/tmp/tstpopen.tmp", "w");
+  output = popen ("/bin/cat >" OBJPFX "tstpopen.tmp", "w");
   if (output == NULL)
     {
       perror ("popen");
@@ -69,10 +69,10 @@  do_test (void)
   write_data (output);
   wstatus = pclose (output);
   printf ("writing pclose returned %d\n", wstatus);
-  input = popen ("/bin/cat /tmp/tstpopen.tmp", "r");
+  input = popen ("/bin/cat " OBJPFX "tstpopen.tmp", "r");
   if (input == NULL)
     {
-      perror ("/tmp/tstpopen.tmp");
+      perror (OBJPFX "tstpopen.tmp");
       puts ("Test FAILED!");
       exit (1);
     }
@@ -80,7 +80,7 @@  do_test (void)
   rstatus = pclose (input);
   printf ("reading pclose returned %d\n", rstatus);
 
-  remove ("/tmp/tstpopen.tmp");
+  remove (OBJPFX "tstpopen.tmp");
 
   errno = 0;
   output = popen ("/bin/cat", "m");
diff --git a/stdio-common/test_rdwr.c b/stdio-common/test_rdwr.c
index f471570..3489873 100644
--- a/stdio-common/test_rdwr.c
+++ b/stdio-common/test_rdwr.c
@@ -38,7 +38,7 @@  main (int argc, char **argv)
   else
     name = *argv;
 
-  (void) sprintf (filename, "/tmp/%s.test", name);
+  (void) sprintf (filename, OBJPFX "%s.test", name);
 
   f = fopen (filename, "w+");
   if (f == NULL)