Merge branch '2580-spawn-close-range-errors' into 'main'

gspawn: Report errors with closing file descriptors between fork/exec

Closes #2580

See merge request GNOME/glib!2435
This commit is contained in:
Philip Withnall 2022-01-19 12:43:57 +00:00
commit 90b40ee3d2

View File

@ -1520,7 +1520,7 @@ safe_fdwalk (int (*cb)(void *data, int fd), void *data)
/* This function is called between fork() and exec() and hence must be
* async-signal-safe (see signal-safety(7)). */
static void
static int
safe_fdwalk_set_cloexec (int lowfd)
{
#if defined(HAVE_CLOSE_RANGE) && defined(CLOSE_RANGE_CLOEXEC)
@ -1534,15 +1534,18 @@ safe_fdwalk_set_cloexec (int lowfd)
* Handle ENOSYS in case its supported in libc but not the kernel; if so,
* fall back to safe_fdwalk(). Handle EINVAL in case `CLOSE_RANGE_CLOEXEC`
* is not supported. */
if (close_range (lowfd, G_MAXUINT, CLOSE_RANGE_CLOEXEC) != 0 &&
(errno == ENOSYS || errno == EINVAL))
int ret = close_range (lowfd, G_MAXUINT, CLOSE_RANGE_CLOEXEC);
if (ret == 0 || !(errno == ENOSYS || errno == EINVAL))
return ret;
#endif /* HAVE_CLOSE_RANGE */
(void) safe_fdwalk (set_cloexec, GINT_TO_POINTER (lowfd));
return safe_fdwalk (set_cloexec, GINT_TO_POINTER (lowfd));
}
/* This function is called between fork() and exec() and hence must be
* async-signal-safe (see signal-safety(7)). */
static void
* async-signal-safe (see signal-safety(7)).
*
* On failure, `-1` will be returned and errno will be set. */
static int
safe_closefrom (int lowfd)
{
#if defined(__FreeBSD__) || defined(__OpenBSD__) || \
@ -1560,6 +1563,7 @@ safe_closefrom (int lowfd)
* On such systems, F_CLOSEFROM is defined.
*/
(void) closefrom (lowfd);
return 0;
#elif defined(__DragonFly__)
/* It is unclear whether closefrom function included in DragonFlyBSD libc_r
* is safe to use because it calls a lot of library functions. It is also
@ -1567,12 +1571,13 @@ safe_closefrom (int lowfd)
* direct system call here ourselves to avoid possible issues.
*/
(void) syscall (SYS_closefrom, lowfd);
return 0;
#elif defined(F_CLOSEM)
/* NetBSD and AIX have a special fcntl command which does the same thing as
* closefrom. NetBSD also includes closefrom function, which seems to be a
* simple wrapper of the fcntl command.
*/
(void) fcntl (lowfd, F_CLOSEM);
return fcntl (lowfd, F_CLOSEM);
#else
#if defined(HAVE_CLOSE_RANGE)
@ -1582,9 +1587,11 @@ safe_closefrom (int lowfd)
*
* Handle ENOSYS in case its supported in libc but not the kernel; if so,
* fall back to safe_fdwalk(). */
if (close_range (lowfd, G_MAXUINT, 0) != 0 && errno == ENOSYS)
int ret = close_range (lowfd, G_MAXUINT, 0);
if (ret == 0 || errno != ENOSYS)
return ret;
#endif /* HAVE_CLOSE_RANGE */
(void) safe_fdwalk (close_func, GINT_TO_POINTER (lowfd));
return safe_fdwalk (close_func, GINT_TO_POINTER (lowfd));
#endif
}
@ -1622,7 +1629,8 @@ enum
CHILD_EXEC_FAILED,
CHILD_OPEN_FAILED,
CHILD_DUP2_FAILED,
CHILD_FORK_FAILED
CHILD_FORK_FAILED,
CHILD_CLOSE_FAILED,
};
/* This function is called between fork() and exec() and hence must be
@ -1738,12 +1746,14 @@ do_exec (gint child_err_report_fd,
if (safe_dup2 (child_err_report_fd, 3) < 0)
write_err_and_exit (child_err_report_fd, CHILD_DUP2_FAILED);
set_cloexec (GINT_TO_POINTER (0), 3);
safe_closefrom (4);
if (safe_closefrom (4) < 0)
write_err_and_exit (child_err_report_fd, CHILD_CLOSE_FAILED);
child_err_report_fd = 3;
}
else
{
safe_fdwalk_set_cloexec (3);
if (safe_fdwalk_set_cloexec (3) < 0)
write_err_and_exit (child_err_report_fd, CHILD_CLOSE_FAILED);
}
}
else
@ -2543,7 +2553,15 @@ fork_exec (gboolean intermediate_child,
_("Failed to fork child process (%s)"),
g_strerror (buf[1]));
break;
case CHILD_CLOSE_FAILED:
g_set_error (error,
G_SPAWN_ERROR,
G_SPAWN_ERROR_FAILED,
_("Failed to close file descriptor for child process (%s)"),
g_strerror (buf[1]));
break;
default:
g_set_error (error,
G_SPAWN_ERROR,