Re: [PATCH 3/3] binderfs_test: switch from /dev to /tmp as mountpoint

On Thu, Mar 12, 2020 at 02:15:31PM +0100, Christian Brauner wrote:

Unprivileged users will be able to create directories in there. The unprivileged test for /dev wouldn't have worked on most systems.

Signed-off-by: Christian Brauner christian.brauner@ubuntu.com

Seems good. (Though would a dynamic location be better? mkstemp()-style?)

Reviewed-by: Kees Cook keescook@chromium.org

-Kees

---

.../filesystems/binderfs/binderfs_test.c | 30 +++++++++---------- 1 file changed, 15 insertions(+), 15 deletions(-)

diff --git a/tools/testing/selftests/filesystems/binderfs/binderfs_test.c b/tools/testing/selftests/filesystems/binderfs/binderfs_test.c index 313ffad15614..d6e61998d20a 100644 --- a/tools/testing/selftests/filesystems/binderfs/binderfs_test.c +++ b/tools/testing/selftests/filesystems/binderfs/binderfs_test.c @@ -76,7 +76,7 @@ static void __do_binderfs_test(void) change_mountns();

• ret = mkdir("/dev/binderfs", 0755);

• ret = mkdir("/tmp/binderfs", 0755); if (ret < 0) { if (errno != EEXIST) ksft_exit_fail_msg(

@@ -86,13 +86,13 @@ static void __do_binderfs_test(void) keep = true; }

• ret = mount(NULL, "/dev/binderfs", "binder", 0, 0);

• ret = mount(NULL, "/tmp/binderfs", "binder", 0, 0); if (ret < 0) { if (errno != ENODEV) ksft_exit_fail_msg("%s - Failed to mount binderfs\n", strerror(errno));

• keep ? : rmdir_protect_errno("/dev/binderfs");
  

• keep ? : rmdir_protect_errno("/tmp/binderfs");
  

  ksft_exit_skip( "The Android binderfs filesystem is not available\n"); }

@@ -102,7 +102,7 @@ static void __do_binderfs_test(void) memcpy(device.name, "my-binder", strlen("my-binder"));

• fd = open("/dev/binderfs/binder-control", O_RDONLY | O_CLOEXEC);

• fd = open("/tmp/binderfs/binder-control", O_RDONLY | O_CLOEXEC); if (fd < 0) ksft_exit_fail_msg( "%s - Failed to open binder-control device\n",

@@ -113,7 +113,7 @@ static void __do_binderfs_test(void) close(fd); errno = saved_errno; if (ret < 0) {

• keep ? : rmdir_protect_errno("/dev/binderfs");
  

• keep ? : rmdir_protect_errno("/tmp/binderfs");
  

  ksft_exit_fail_msg( "%s - Failed to allocate new binder device\n", strerror(errno));

@@ -126,9 +126,9 @@ static void __do_binderfs_test(void) /* binder device allocation test passed */ ksft_inc_pass_cnt();

• fd = open("/dev/binderfs/my-binder", O_CLOEXEC | O_RDONLY);

• fd = open("/tmp/binderfs/my-binder", O_CLOEXEC | O_RDONLY); if (fd < 0) {

• keep ? : rmdir_protect_errno("/dev/binderfs");
  

• keep ? : rmdir_protect_errno("/tmp/binderfs");
  

  ksft_exit_fail_msg("%s - Failed to open my-binder device\n", strerror(errno)); }

@@ -138,7 +138,7 @@ static void __do_binderfs_test(void) close(fd); errno = saved_errno; if (ret < 0) {

• keep ? : rmdir_protect_errno("/dev/binderfs");
  

• keep ? : rmdir_protect_errno("/tmp/binderfs");
  

  ksft_exit_fail_msg( "%s - Failed to open perform BINDER_VERSION request\n", strerror(errno));

@@ -150,9 +150,9 @@ static void __do_binderfs_test(void) /* binder transaction with binderfs binder device passed */ ksft_inc_pass_cnt();

• ret = unlink("/dev/binderfs/my-binder");

• ret = unlink("/tmp/binderfs/my-binder"); if (ret < 0) {

• keep ? : rmdir_protect_errno("/dev/binderfs");
  

• keep ? : rmdir_protect_errno("/tmp/binderfs");
  

  ksft_exit_fail_msg("%s - Failed to delete binder device\n", strerror(errno)); }

@@ -160,12 +160,12 @@ static void __do_binderfs_test(void) /* binder device removal passed */ ksft_inc_pass_cnt();

• ret = unlink("/dev/binderfs/binder-control");

• ret = unlink("/tmp/binderfs/binder-control"); if (!ret) {

• keep ? : rmdir_protect_errno("/dev/binderfs");
  

• keep ? : rmdir_protect_errno("/tmp/binderfs");
  

  ksft_exit_fail_msg("Managed to delete binder-control device\n"); } else if (errno != EPERM) {

• keep ? : rmdir_protect_errno("/dev/binderfs");
  

• keep ? : rmdir_protect_errno("/tmp/binderfs");
  

  ksft_exit_fail_msg( "%s - Failed to delete binder-control device but exited with unexpected error code\n", strerror(errno));

@@ -175,8 +175,8 @@ static void __do_binderfs_test(void) ksft_inc_xfail_cnt(); on_error:

• ret = umount2("/dev/binderfs", MNT_DETACH);
• keep ?: rmdir_protect_errno("/dev/binderfs");

• ret = umount2("/tmp/binderfs", MNT_DETACH);
• keep ?: rmdir_protect_errno("/tmp/binderfs"); if (ret < 0) ksft_exit_fail_msg("%s - Failed to unmount binderfs\n", strerror(errno));

-- 2.25.1