Fix the %P logfile escape inside a chroot.

3 files changed, 72 insertions, 46 deletions

diff --git a/clientserver.c b/clientserver.c
index f78c61c3..9500bf01 100644
--- a/clientserver.c
+++ b/clientserver.c
@@ -75,6 +75,8 @@ struct chmod_mode_struct *daemon_chmod_modes;
 char *module_dir = NULL;
 unsigned int module_dirlen = 0;
 
+char *full_module_path;
+
 static int rl_nulls = 0;
 
 #ifdef HAVE_SIGACTION
@@ -395,10 +397,20 @@ static int read_arg_from_pipe(int fd, char *buf, int limit)
 	return bp - buf;
 }
 
+static int path_failure(int f_out, const char *dir, BOOL was_chdir)
+{
+	if (was_chdir)
+		rsyserr(FLOG, errno, "chdir %s failed\n", dir);
+	else
+		rprintf(FLOG, "normalize_path(%s) failed\n", dir);
+	io_printf(f_out, "@ERROR: chdir failed\n");
+	return -1;
+}
+
 static int rsync_module(int f_in, int f_out, int i, char *addr, char *host)
 {
 	int argc;
-	char **argv, **orig_argv, **orig_early_argv, *chroot_path = NULL;
+	char **argv, **orig_argv, **orig_early_argv, *module_chdir;
 	char line[BIGPATHBUFLEN];
 	uid_t uid = (uid_t)-2;  /* canonically "nobody" */
 	gid_t gid = (gid_t)-2;
@@ -501,27 +513,27 @@ static int rsync_module(int f_in, int f_out, int i, char *addr, char *host)
 	module_dir = lp_path(i);
 	if (use_chroot) {
 		if ((p = strstr(module_dir, "/./")) != NULL) {
-			*p = '\0';
-			p += 2;
-		} else if ((p = strdup("/")) == NULL) /* MEMORY LEAK */
-			out_of_memory("rsync_module");
-	}
-
-	/* We do a change_dir() that doesn't actually call chdir()
-	 * just to make a relative path absolute. */
-	strlcpy(line, curr_dir, sizeof line);
-	if (!change_dir(module_dir, CD_SKIP_CHDIR))
-		goto chdir_failed;
-	if (strcmp(curr_dir, module_dir) != 0
-	 && (module_dir = strdup(curr_dir)) == NULL)
-		out_of_memory("rsync_module");
-	change_dir(line, CD_SKIP_CHDIR); /* Restore curr_dir. */
-
-	if (use_chroot) {
-		chroot_path = module_dir;
-		module_dir = p; /* p is "/" or our inside-chroot path */
+			*p = '\0'; /* Temporary... */
+			if (!(module_chdir = normalize_path(module_dir, True, NULL)))
+				return path_failure(f_out, module_dir, False);
+			*p = '/';
+			if (!(p = normalize_path(p + 2, True, &module_dirlen)))
+				return path_failure(f_out, strstr(module_dir, "/./"), False);
+			if (!(full_module_path = normalize_path(module_dir, False, NULL)))
+				full_module_path = module_dir;
+			module_dir = p;
+		} else {
+			if (!(module_chdir = normalize_path(module_dir, False, NULL)))
+				return path_failure(f_out, module_dir, False);
+			full_module_path = module_chdir;
+			module_dir = "/";
+			module_dirlen = 1;
+		}
+	} else {
+		if (!(module_chdir = normalize_path(module_dir, False, &module_dirlen)))
+			return path_failure(f_out, module_dir, False);
+		full_module_path = module_dir = module_chdir;
 	}
-	module_dirlen = clean_fname(module_dir, CFN_COLLAPSE_DOT_DOT_DIRS | CFN_DROP_TRAILING_DOT_DIR);
 
 	if (module_dirlen == 1) {
 		module_dirlen = 0;
@@ -557,16 +569,8 @@ static int rsync_module(int f_in, int f_out, int i, char *addr, char *host)
 		char *modname, *modpath, *hostaddr, *hostname, *username;
 		int status;
 
-		if (!use_chroot)
-			p = module_dir;
-		else if (module_dirlen) {
-			pathjoin(line, sizeof line, chroot_path, module_dir+1);
-			p = line;
-		} else
-			p = chroot_path;
-
 		if (asprintf(&modname, "RSYNC_MODULE_NAME=%s", name) < 0
-		 || asprintf(&modpath, "RSYNC_MODULE_PATH=%s", p) < 0
+		 || asprintf(&modpath, "RSYNC_MODULE_PATH=%s", full_module_path) < 0
 		 || asprintf(&hostaddr, "RSYNC_HOST_ADDR=%s", addr) < 0
 		 || asprintf(&hostname, "RSYNC_HOST_NAME=%s", host) < 0
 		 || asprintf(&username, "RSYNC_USER_NAME=%s", auth_user) < 0)
@@ -666,25 +670,19 @@ static int rsync_module(int f_in, int f_out, int i, char *addr, char *host)
 		 * a warning, unless a "require chroot" flag is set,
 		 * in which case we fail.
 		 */
-		if (chroot(chroot_path)) {
-			rsyserr(FLOG, errno, "chroot %s failed", chroot_path);
+		if (chroot(module_chdir)) {
+			rsyserr(FLOG, errno, "chroot %s failed", module_chdir);
 			io_printf(f_out, "@ERROR: chroot failed\n");
 			return -1;
 		}
-		if (!change_dir(module_dir, CD_NORMAL))
-			goto chdir_failed;
-		if (module_dirlen)
-			sanitize_paths = 1;
-	} else {
-		if (!change_dir(module_dir, CD_NORMAL)) {
-		  chdir_failed:
-			rsyserr(FLOG, errno, "chdir %s failed\n", module_dir);
-			io_printf(f_out, "@ERROR: chdir failed\n");
-			return -1;
-		}
-		sanitize_paths = 1;
+		module_chdir = module_dir;
 	}
 
+	if (!change_dir(module_chdir, CD_NORMAL))
+		return path_failure(f_out, module_chdir, True);
+	if (module_dirlen || !use_chroot)
+		sanitize_paths = 1;
+
 	if ((munge_symlinks = lp_munge_symlinks(i)) < 0)
 		munge_symlinks = !use_chroot || module_dirlen;
 	if (munge_symlinks) {
diff --git a/log.c b/log.c
index 2dfa1275..1e18c9e1 100644
--- a/log.c
+++ b/log.c
@@ -55,7 +55,7 @@ extern iconv_t ic_chck;
 extern iconv_t ic_send, ic_recv;
 #endif
 extern char curr_dir[];
-extern char *module_dir;
+extern char *full_module_path;
 extern unsigned int module_dirlen;
 
 static int log_initialised;
@@ -603,7 +603,7 @@ static void log_formatted(enum logcode code, const char *format, const char *op,
 			n = timestring(time(NULL));
 			break;
 		case 'P':
-			n = module_dir;
+			n = full_module_path;
 			break;
 		case 'u':
 			n = auth_user;
diff --git a/util.c b/util.c
index 634f9cf5..2f7ea914 100644
--- a/util.c
+++ b/util.c
@@ -1025,6 +1025,34 @@ int change_dir(const char *dir, int set_path_only)
 	return 1;
 }
 
+/* This will make a relative path absolute and clean it up via clean_fname().
+ * Returns the string, which might be newly allocated, or NULL on error. */
+char *normalize_path(char *path, BOOL force_newbuf, unsigned int *len_ptr)
+{
+	unsigned int len;
+
+	if (*path != '/') { /* Make path absolute. */
+		int len = strlen(path);
+		if (curr_dir_len + 1 + len >= sizeof curr_dir)
+			return NULL;
+		curr_dir[curr_dir_len] = '/';
+		memcpy(curr_dir + curr_dir_len + 1, path, len + 1);
+		if (!(path = strdup(curr_dir)))
+			out_of_memory("normalize_path");
+		curr_dir[curr_dir_len] = '\0';
+	} else if (force_newbuf) {
+		if (!(path = strdup(path)))
+			out_of_memory("normalize_path");
+	}
+
+	len = clean_fname(path, CFN_COLLAPSE_DOT_DOT_DIRS | CFN_DROP_TRAILING_DOT_DIR);
+
+	if (len_ptr)
+		*len_ptr = len;
+
+	return path;
+}
+
 /**
  * Return a quoted string with the full pathname of the indicated filename.
  * The string " (in MODNAME)" may also be appended.  The returned pointer