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authorDamien Miller <djm@mindrot.org>2005-07-17 17:19:24 +1000
committerDamien Miller <djm@mindrot.org>2005-07-17 17:19:24 +1000
commit2b9b045d930b8d724f768fafdd9a46fa453b9a3e (patch)
treef127eb67a0f4818cbb429b7faa76330e7659a6c5
parent37294fb6307202e6f52d7046b3ddb56a4786d27f (diff)
downloadopenssh-git-2b9b045d930b8d724f768fafdd9a46fa453b9a3e.tar.gz
- (djm) [auth-pam.c sftp.c] spaces vs. tabs at start of line
- djm@cvs.openbsd.org 2005/07/17 06:49:04 [channels.c channels.h session.c session.h] Fix a number of X11 forwarding channel leaks: 1. Refuse multiple X11 forwarding requests on the same session 2. Clean up all listeners after a single_connection X11 forward, not just the one that made the single connection 3. Destroy X11 listeners when the session owning them goes away testing and ok dtucker@
-rw-r--r--ChangeLog10
-rw-r--r--channels.c10
-rw-r--r--channels.h4
-rw-r--r--session.c106
-rw-r--r--session.h3
5 files changed, 125 insertions, 8 deletions
diff --git a/ChangeLog b/ChangeLog
index 647ad016..84b82ccc 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -8,6 +8,14 @@
[cipher-acss.c loginrec.c ssh-rand-helper.c sshd.c] Fix whitespace at EOL
in portable too ("perl -p -i -e 's/\s+$/\n/' *.[ch]")
- (djm) [auth-pam.c sftp.c] spaces vs. tabs at start of line
+ - djm@cvs.openbsd.org 2005/07/17 06:49:04
+ [channels.c channels.h session.c session.h]
+ Fix a number of X11 forwarding channel leaks:
+ 1. Refuse multiple X11 forwarding requests on the same session
+ 2. Clean up all listeners after a single_connection X11 forward, not just
+ the one that made the single connection
+ 3. Destroy X11 listeners when the session owning them goes away
+ testing and ok dtucker@
20050716
- (dtucker) [auth-pam.c] Ensure that only one side of the authentication
@@ -2841,4 +2849,4 @@
- (djm) Trim deprecated options from INSTALL. Mention UsePAM
- (djm) Fix quote handling in sftp; Patch from admorten AT umich.edu
-$Id: ChangeLog,v 1.3849 2005/07/17 07:18:49 djm Exp $
+$Id: ChangeLog,v 1.3850 2005/07/17 07:19:24 djm Exp $
diff --git a/channels.c b/channels.c
index b7ff8500..8da399b6 100644
--- a/channels.c
+++ b/channels.c
@@ -39,7 +39,7 @@
*/
#include "includes.h"
-RCSID("$OpenBSD: channels.c,v 1.221 2005/07/16 01:35:24 djm Exp $");
+RCSID("$OpenBSD: channels.c,v 1.222 2005/07/17 06:49:04 djm Exp $");
#include "ssh.h"
#include "ssh1.h"
@@ -2659,7 +2659,7 @@ channel_send_window_changes(void)
*/
int
x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
- int single_connection, u_int *display_numberp)
+ int single_connection, u_int *display_numberp, int **chanids)
{
Channel *nc = NULL;
int display_number, sock;
@@ -2749,6 +2749,8 @@ x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
}
/* Allocate a channel for each socket. */
+ if (chanids != NULL)
+ *chanids = xmalloc(sizeof(**chanids) * (num_socks + 1));
for (n = 0; n < num_socks; n++) {
sock = socks[n];
nc = channel_new("x11 listener",
@@ -2756,7 +2758,11 @@ x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
0, "X11 inet listener", 1);
nc->single_connection = single_connection;
+ if (*chanids != NULL)
+ (*chanids)[n] = nc->self;
}
+ if (*chanids != NULL)
+ (*chanids)[n] = -1;
/* Return the display number for the DISPLAY environment variable. */
*display_numberp = display_number;
diff --git a/channels.h b/channels.h
index b89b7c95..1cb2c3a3 100644
--- a/channels.h
+++ b/channels.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: channels.h,v 1.78 2005/07/08 09:41:33 markus Exp $ */
+/* $OpenBSD: channels.h,v 1.79 2005/07/17 06:49:04 djm Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
@@ -214,7 +214,7 @@ int channel_cancel_rport_listener(const char *, u_short);
/* x11 forwarding */
int x11_connect_display(void);
-int x11_create_display_inet(int, int, int, u_int *);
+int x11_create_display_inet(int, int, int, u_int *, int **);
void x11_input_open(int, u_int32_t, void *);
void x11_request_forwarding_with_spoofing(int, const char *, const char *,
const char *);
diff --git a/session.c b/session.c
index 13c3b001..81d7d53e 100644
--- a/session.c
+++ b/session.c
@@ -33,7 +33,7 @@
*/
#include "includes.h"
-RCSID("$OpenBSD: session.c,v 1.183 2005/07/16 01:35:24 djm Exp $");
+RCSID("$OpenBSD: session.c,v 1.184 2005/07/17 06:49:04 djm Exp $");
#include "ssh.h"
#include "ssh1.h"
@@ -1634,6 +1634,7 @@ session_new(void)
s->ttyfd = -1;
s->used = 1;
s->self = i;
+ s->x11_chanids = NULL;
debug("session_new: session %d", i);
return s;
}
@@ -1707,6 +1708,29 @@ session_by_channel(int id)
}
static Session *
+session_by_x11_channel(int id)
+{
+ int i, j;
+
+ for (i = 0; i < MAX_SESSIONS; i++) {
+ Session *s = &sessions[i];
+
+ if (s->x11_chanids == NULL || !s->used)
+ continue;
+ for (j = 0; s->x11_chanids[j] != -1; j++) {
+ if (s->x11_chanids[j] == id) {
+ debug("session_by_x11_channel: session %d "
+ "channel %d", s->self, id);
+ return s;
+ }
+ }
+ }
+ debug("session_by_x11_channel: unknown channel %d", id);
+ session_dump();
+ return NULL;
+}
+
+static Session *
session_by_pid(pid_t pid)
{
int i;
@@ -1835,6 +1859,11 @@ session_x11_req(Session *s)
{
int success;
+ if (s->auth_proto != NULL || s->auth_data != NULL) {
+ error("session_x11_req: session %d: "
+ "x11 fowarding already active", s->self);
+ return 0;
+ }
s->single_connection = packet_get_char();
s->auth_proto = packet_get_string(NULL);
s->auth_data = packet_get_string(NULL);
@@ -2060,9 +2089,66 @@ sig2name(int sig)
}
static void
+session_close_x11(int id)
+{
+ Channel *c;
+
+ if ((c = channel_lookup(id)) == NULL) {
+ debug("session_close_x11: x11 channel %d missing", id);
+ } else {
+ /* Detach X11 listener */
+ debug("session_close_x11: detach x11 channel %d", id);
+ channel_cancel_cleanup(id);
+ if (c->ostate != CHAN_OUTPUT_CLOSED)
+ chan_mark_dead(c);
+ }
+}
+
+static void
+session_close_single_x11(int id, void *arg)
+{
+ Session *s;
+ u_int i;
+
+ debug3("session_close_single_x11: channel %d", id);
+ channel_cancel_cleanup(id);
+ if ((s = session_by_x11_channel(id)) == NULL)
+ fatal("session_close_single_x11: no x11 channel %d", id);
+ for (i = 0; s->x11_chanids[i] != -1; i++) {
+ debug("session_close_single_x11: session %d: "
+ "closing channel %d", s->self, s->x11_chanids[i]);
+ /*
+ * The channel "id" is already closing, but make sure we
+ * close all of its siblings.
+ */
+ if (s->x11_chanids[i] != id)
+ session_close_x11(s->x11_chanids[i]);
+ }
+ xfree(s->x11_chanids);
+ s->x11_chanids = NULL;
+ if (s->display) {
+ xfree(s->display);
+ s->display = NULL;
+ }
+ if (s->auth_proto) {
+ xfree(s->auth_proto);
+ s->auth_proto = NULL;
+ }
+ if (s->auth_data) {
+ xfree(s->auth_data);
+ s->auth_data = NULL;
+ }
+ if (s->auth_display) {
+ xfree(s->auth_display);
+ s->auth_display = NULL;
+ }
+}
+
+static void
session_exit_message(Session *s, int status)
{
Channel *c;
+ u_int i;
if ((c = channel_lookup(s->chanid)) == NULL)
fatal("session_exit_message: session %d: no channel %d",
@@ -2102,6 +2188,14 @@ session_exit_message(Session *s, int status)
if (c->ostate != CHAN_OUTPUT_CLOSED)
chan_write_failed(c);
s->chanid = -1;
+
+ /* Close any X11 listeners associated with this session */
+ if (s->x11_chanids != NULL) {
+ for (i = 0; s->x11_chanids[i] != -1; i++) {
+ session_close_x11(s->x11_chanids[i]);
+ s->x11_chanids[i] = -1;
+ }
+ }
}
void
@@ -2116,6 +2210,8 @@ session_close(Session *s)
xfree(s->term);
if (s->display)
xfree(s->display);
+ if (s->x11_chanids)
+ xfree(s->x11_chanids);
if (s->auth_display)
xfree(s->auth_display);
if (s->auth_data)
@@ -2154,6 +2250,7 @@ void
session_close_by_channel(int id, void *arg)
{
Session *s = session_by_channel(id);
+
if (s == NULL) {
debug("session_close_by_channel: no session for id %d", id);
return;
@@ -2234,6 +2331,7 @@ session_setup_x11fwd(Session *s)
struct stat st;
char display[512], auth_display[512];
char hostname[MAXHOSTNAMELEN];
+ u_int i;
if (no_x11_forwarding_flag) {
packet_send_debug("X11 forwarding disabled in user configuration file.");
@@ -2259,10 +2357,14 @@ session_setup_x11fwd(Session *s)
}
if (x11_create_display_inet(options.x11_display_offset,
options.x11_use_localhost, s->single_connection,
- &s->display_number) == -1) {
+ &s->display_number, &s->x11_chanids) == -1) {
debug("x11_create_display_inet failed.");
return 0;
}
+ for (i = 0; s->x11_chanids[i] != -1; i++) {
+ channel_register_cleanup(s->x11_chanids[i],
+ session_close_single_x11);
+ }
/* Set up a suitable value for the DISPLAY variable. */
if (gethostname(hostname, sizeof(hostname)) < 0)
diff --git a/session.h b/session.h
index 92bd1657..a2598a99 100644
--- a/session.h
+++ b/session.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: session.h,v 1.24 2005/06/17 02:44:33 djm Exp $ */
+/* $OpenBSD: session.h,v 1.25 2005/07/17 06:49:04 djm Exp $ */
/*
* Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
@@ -49,6 +49,7 @@ struct Session {
int single_connection;
/* proto 2 */
int chanid;
+ int *x11_chanids;
int is_subsystem;
u_int num_env;
struct {