From 35c2958ae4caf70a3074f59fbceeb24cfe82f902 Mon Sep 17 00:00:00 2001
From: nicm <nicm>
Date: Tue, 6 Jul 2021 08:18:38 +0000
Subject: Forbid empty session names, GitHub issue 2758.

---
 cmd-new-session.c    | 13 ++++++++++++-
 cmd-rename-session.c |  5 +++++
 session.c            |  2 ++
 3 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/cmd-new-session.c b/cmd-new-session.c
index c47d66cd..666aeaac 100644
--- a/cmd-new-session.c
+++ b/cmd-new-session.c
@@ -102,6 +102,11 @@ cmd_new_session_exec(struct cmd *self, struct cmdq_item *item)
 	if (tmp != NULL) {
 		name = format_single(item, tmp, c, NULL, NULL, NULL);
 		newname = session_check_name(name);
+		if (newname == NULL) {
+			cmdq_error(item, "invalid session: %s", name);
+			free(name);
+			return (CMD_RETURN_ERROR);
+		}
 		free(name);
 	}
 	if (args_has(args, 'A')) {
@@ -134,8 +139,14 @@ cmd_new_session_exec(struct cmd *self, struct cmdq_item *item)
 			prefix = xstrdup(sg->name);
 		else if (groupwith != NULL)
 			prefix = xstrdup(groupwith->name);
-		else
+		else {
 			prefix = session_check_name(group);
+			if (prefix == NULL) {
+				cmdq_error(item, "invalid session group: %s",
+				    group);
+				goto fail;
+			}
+		}
 	}
 
 	/* Set -d if no client. */
diff --git a/cmd-rename-session.c b/cmd-rename-session.c
index 51b8ffc8..49fafe33 100644
--- a/cmd-rename-session.c
+++ b/cmd-rename-session.c
@@ -53,6 +53,11 @@ cmd_rename_session_exec(struct cmd *self, struct cmdq_item *item)
 
 	tmp = format_single_from_target(item, args->argv[0]);
 	newname = session_check_name(tmp);
+	if (newname == NULL) {
+		cmdq_error(item, "invalid session: %s", tmp);
+		free(tmp);
+		return (CMD_RETURN_ERROR);
+	}
 	free(tmp);
 	if (strcmp(newname, s->name) == 0) {
 		free(newname);
diff --git a/session.c b/session.c
index 93d50b47..cb0093a2 100644
--- a/session.c
+++ b/session.c
@@ -237,6 +237,8 @@ session_check_name(const char *name)
 {
 	char	*copy, *cp, *new_name;
 
+	if (*name == '\0')
+		return (NULL);
 	copy = xstrdup(name);
 	for (cp = copy; *cp != '\0'; cp++) {
 		if (*cp == ':' || *cp == '.')
-- 
cgit 


From 32f2d9d089ced7d693aa412821f1d66134877cf0 Mon Sep 17 00:00:00 2001
From: nicm <nicm>
Date: Tue, 6 Jul 2021 08:26:00 +0000
Subject: Improve error reporting when the tmux /tmp directory cannot be
 created or used, GitHub issue 2765 from Uwe Kleine-Koenig.

---
 tmux.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/tmux.c b/tmux.c
index 16877407..55ab9751 100644
--- a/tmux.c
+++ b/tmux.c
@@ -211,16 +211,22 @@ make_label(const char *label, char **cause)
 	free(paths);
 
 	xasprintf(&base, "%s/tmux-%ld", path, (long)uid);
-	if (mkdir(base, S_IRWXU) != 0 && errno != EEXIST)
+	if (mkdir(base, S_IRWXU) != 0 && errno != EEXIST) {
+		xasprintf(cause, "couldn't create directory %s (%s)", base,
+		    strerror(errno));
 		goto fail;
-	if (lstat(base, &sb) != 0)
+	}
+	if (lstat(base, &sb) != 0) {
+		xasprintf(cause, "couldn't read directory %s (%s)", base,
+		    strerror(errno));
 		goto fail;
+	}
 	if (!S_ISDIR(sb.st_mode)) {
-		errno = ENOTDIR;
+		xasprintf(cause, "%s is not a directory", base);
 		goto fail;
 	}
 	if (sb.st_uid != uid || (sb.st_mode & S_IRWXO) != 0) {
-		errno = EACCES;
+		xasprintf(cause, "directory %s has unsafe permissions", base);
 		goto fail;
 	}
 	xasprintf(&path, "%s/%s", base, label);
@@ -228,7 +234,6 @@ make_label(const char *label, char **cause)
 	return (path);
 
 fail:
-	xasprintf(cause, "error creating %s (%s)", base, strerror(errno));
 	free(base);
 	return (NULL);
 }
-- 
cgit