glib/gio/gsubprocesslauncher-private.h
Philip Withnall 55a75590d0 gsubprocesslauncher: Don’t close target FDs in close() method
This is a regression introduced in commit 67a589e505. Previously, the
source/target FD pairs were stored in `needdup_fd_assignments`, in
consecutive entries, so source FDs had even indices and target FDs had
odd indices.

I didn’t notice that the array index was being incremented by 2 when
closing FDs, when porting from the old code. So previously the code was
only closing the source FDs; after the port, it was closing source and
target FDs.

That’s incorrect, as the target FDs are just integers in the parent
process. It’s only in the child process where they are actually FDs —
and `g_subprocess_launcher_close()` is never called in the child
process.

This resulted in some strange misbehaviours in any process which used
`g_subprocess_launcher_take_fd()` with target FDs which could have
possibly aliased with other FDs in the parent process (and which weren’t
equal to their mapped source FDs).

Thanks to Olivier Fourdan for the detailed bug report.

Signed-off-by: Philip Withnall <pwithnall@endlessos.org>

Fixes: #2332
2021-02-19 18:27:00 +00:00

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1.7 KiB
C

/* GIO - GLib Input, Output and Streaming Library
*
* Copyright (C) 2012 Colin Walters <walters@verbum.org>
*
* This 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.
*
* This 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 this library; if not, see <http://www.gnu.org/licenses/>.
*/
#ifndef __G_SUBPROCESS_CONTEXT_PRIVATE_H__
#define __G_SUBPROCESS_CONTEXT_PRIVATE_H__
#include "gsubprocesslauncher.h"
G_BEGIN_DECLS
struct _GSubprocessLauncher
{
GObject parent;
GSubprocessFlags flags;
gboolean path_from_envp;
char **envp;
char *cwd;
#ifdef G_OS_UNIX
gint stdin_fd;
gchar *stdin_path;
gint stdout_fd;
gchar *stdout_path;
gint stderr_fd;
gchar *stderr_path;
GArray *source_fds; /* GSubprocessLauncher has ownership of the FD elements */
GArray *target_fds; /* always the same length as source_fds; elements are just integers and not FDs in this process */
gboolean closed_fd;
GSpawnChildSetupFunc child_setup_func;
gpointer child_setup_user_data;
GDestroyNotify child_setup_destroy_notify;
#endif
};
void g_subprocess_set_launcher (GSubprocess *subprocess,
GSubprocessLauncher *launcher);
G_END_DECLS
#endif