common: Fix gnupg_reopen_std.

* common/sysutils.c (gnupg_reopen_std): Use fcntl instead of fstat.

--

When gpg was invoked by a Perl web application on FreeBSD, fstat in
gnupg_reopen_std failed with EBADF.  Using fcntl, which is considered
lighter than fstat, it works fine.  Since uur purpose is to check if
file descriptor is valid or not, lighter operation is better.

Reported-by: Marcin Gryszkalis <mg@fork.pl>
Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>
This commit is contained in:
NIIBE Yutaka 2018-10-02 14:22:24 +09:00
parent 0cb65564e0
commit 50b02dba20
1 changed files with 5 additions and 6 deletions

View File

@ -551,14 +551,13 @@ gnupg_tmpfile (void)
void
gnupg_reopen_std (const char *pgmname)
{
#if defined(HAVE_STAT) && !defined(HAVE_W32_SYSTEM)
struct stat statbuf;
#ifdef F_GETFD
int did_stdin = 0;
int did_stdout = 0;
int did_stderr = 0;
FILE *complain;
if (fstat (STDIN_FILENO, &statbuf) == -1 && errno ==EBADF)
if (fcntl (STDIN_FILENO, F_GETFD) == -1 && errno ==EBADF)
{
if (open ("/dev/null",O_RDONLY) == STDIN_FILENO)
did_stdin = 1;
@ -566,7 +565,7 @@ gnupg_reopen_std (const char *pgmname)
did_stdin = 2;
}
if (fstat (STDOUT_FILENO, &statbuf) == -1 && errno == EBADF)
if (fcntl (STDOUT_FILENO, F_GETFD) == -1 && errno == EBADF)
{
if (open ("/dev/null",O_WRONLY) == STDOUT_FILENO)
did_stdout = 1;
@ -574,7 +573,7 @@ gnupg_reopen_std (const char *pgmname)
did_stdout = 2;
}
if (fstat (STDERR_FILENO, &statbuf)==-1 && errno==EBADF)
if (fcntl (STDERR_FILENO, F_GETFD)==-1 && errno==EBADF)
{
if (open ("/dev/null", O_WRONLY) == STDERR_FILENO)
did_stderr = 1;
@ -607,7 +606,7 @@ gnupg_reopen_std (const char *pgmname)
if (did_stdin == 2 || did_stdout == 2 || did_stderr == 2)
exit (3);
#else /* !(HAVE_STAT && !HAVE_W32_SYSTEM) */
#else /* !F_GETFD */
(void)pgmname;
#endif
}