upstream: fix Include before Match in sshd_config; bz#3122 patch

from Jakub Jelen

OpenBSD-Commit-ID: 1b0aaf135fe6732b5d326946042665dd3beba5f4

1 files changed, 21 insertions, 10 deletions

diff --git a/servconf.c b/servconf.c
index 391f4e827..bd8df7fce 100644
--- a/servconf.c
+++ b/servconf.c
@@ -1,5 +1,5 @@
 
-/* $OpenBSD: servconf.c,v 1.364 2020/05/27 21:59:11 djm Exp $ */
+/* $OpenBSD: servconf.c,v 1.365 2020/05/27 22:37:53 djm Exp $ */
 /*
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
  *                    All rights reserved
@@ -550,6 +550,7 @@ typedef enum {
 #define SSHCFG_MATCH            0x02    /* allowed inside a Match section */
 #define SSHCFG_ALL              (SSHCFG_GLOBAL|SSHCFG_MATCH)
 #define SSHCFG_NEVERMATCH       0x04  /* Match never matches; internal only */
+#define SSHCFG_MATCH_ONLY       0x08  /* Match only in conditional blocks; internal only */
 
 /* Textual representation of the tokens. */
 static struct {
@@ -1259,7 +1260,7 @@ static const struct multistate multistate_tcpfwd[] = {
 static int
 process_server_config_line_depth(ServerOptions *options, char *line,
     const char *filename, int linenum, int *activep,
-    struct connection_info *connectinfo, int inc_flags, int depth,
+    struct connection_info *connectinfo, int *inc_flags, int depth,
     struct include_list *includes)
 {
         char ch, *cp, ***chararrayptr, **charptr, *arg, *arg2, *p;
@@ -2002,7 +2003,9 @@ process_server_config_line_depth(ServerOptions *options, char *line,
                                         parse_server_config_depth(options,
                                             item->filename, item->contents,
                                             includes, connectinfo,
-                                            (oactive ? 0 : SSHCFG_NEVERMATCH),
+                                            (*inc_flags & SSHCFG_MATCH_ONLY
+                                                ? SSHCFG_MATCH_ONLY : (oactive
+                                                    ? 0 : SSHCFG_NEVERMATCH)),
                                             activep, depth + 1);
                                 }
                                 found = 1;
@@ -2050,7 +2053,9 @@ process_server_config_line_depth(ServerOptions *options, char *line,
                                 parse_server_config_depth(options,
                                     item->filename, item->contents,
                                     includes, connectinfo,
-                                    (oactive ? 0 : SSHCFG_NEVERMATCH),
+                                    (*inc_flags & SSHCFG_MATCH_ONLY
+                                        ? SSHCFG_MATCH_ONLY : (oactive
+                                            ? 0 : SSHCFG_NEVERMATCH)),
                                     activep, depth + 1);
                                 *activep = oactive;
                                 TAILQ_INSERT_TAIL(includes, item, entry);
@@ -2068,11 +2073,14 @@ process_server_config_line_depth(ServerOptions *options, char *line,
                 if (cmdline)
                         fatal("Match directive not supported as a command-line "
                            "option");
-                value = match_cfg_line(&cp, linenum, connectinfo);
+                value = match_cfg_line(&cp, linenum,
+                    (*inc_flags & SSHCFG_NEVERMATCH ? NULL : connectinfo));
                 if (value < 0)
                         fatal("%s line %d: Bad Match condition", filename,
                             linenum);
-                *activep = (inc_flags & SSHCFG_NEVERMATCH) ? 0 : value;
+                *activep = (*inc_flags & SSHCFG_NEVERMATCH) ? 0 : value;
+                /* The MATCH_ONLY is applicable only until the first match block */
+                *inc_flags &= ~SSHCFG_MATCH_ONLY;
                 break;
 
         case sPermitListen:
@@ -2375,8 +2383,10 @@ process_server_config_line(ServerOptions *options, char *line,
     const char *filename, int linenum, int *activep,
     struct connection_info *connectinfo, struct include_list *includes)
 {
+        int inc_flags = 0;
+
         return process_server_config_line_depth(options, line, filename,
-            linenum, activep, connectinfo, 0, 0, includes);
+            linenum, activep, connectinfo, &inc_flags, 0, includes);
 }
 
 
@@ -2581,14 +2591,15 @@ parse_server_config_depth(ServerOptions *options, const char *filename,
         if (depth < 0 || depth > SERVCONF_MAX_DEPTH)
                 fatal("Too many recursive configuration includes");
 
-        debug2("%s: config %s len %zu", __func__, filename, sshbuf_len(conf));
+        debug2("%s: config %s len %zu%s", __func__, filename, sshbuf_len(conf),
+            (flags & SSHCFG_NEVERMATCH ? " [checking syntax only]" : ""));
 
         if ((obuf = cbuf = sshbuf_dup_string(conf)) == NULL)
                 fatal("%s: sshbuf_dup_string failed", __func__);
         linenum = 1;
         while ((cp = strsep(&cbuf, "\n")) != NULL) {
                 if (process_server_config_line_depth(options, cp,
-                    filename, linenum++, activep, connectinfo, flags,
+                    filename, linenum++, activep, connectinfo, &flags,
                     depth, includes) != 0)
                         bad_options++;
         }
@@ -2605,7 +2616,7 @@ parse_server_config(ServerOptions *options, const char *filename,
 {
         int active = connectinfo ? 0 : 1;
         parse_server_config_depth(options, filename, conf, includes,
-            connectinfo, 0, &active, 0);
+            connectinfo, (connectinfo ? SSHCFG_MATCH_ONLY : 0), &active, 0);
         process_queued_listen_addrs(options);
 }