imap-acl: Check if ACL context is enabled for a namespace before accessing it

This will prevent a crash when accessing an ACL context from a user that
doesn't exist and return an appropriate NONEXISTENT message.

diff --git a/src/plugins/imap-acl/imap-acl-plugin.c b/src/plugins/imap-acl/imap-acl-plugin.c
index c22382d632e3bf7e30cbe6a3b72f989b63b320bb..9065e70210da9c0346e4dade3c24fc891a2651fd 100644 (file)
--- a/src/plugins/imap-acl/imap-acl-plugin.c
+++ b/src/plugins/imap-acl/imap-acl-plugin.c
@@ -625,6 +625,26 @@ static void imap_acl_cmd_getacl(struct mailbox *box, struct mail_namespace *ns,
        }
 }
 
+static struct mail_namespace *
+imap_acl_find_namespace(struct client_command_context *cmd,
+                       const char **mailbox)
+{
+       struct mail_namespace *ns;
+
+       ns = client_find_namespace(cmd, mailbox);
+       if (ns == NULL)
+               return NULL;
+
+       if (ACL_LIST_CONTEXT(ns->list) == NULL) {
+               client_send_tagline(cmd, t_strdup_printf(
+                       "NO ["IMAP_RESP_CODE_NONEXISTENT"] "
+                       MAIL_ERRSTR_MAILBOX_NOT_FOUND, *mailbox));
+               return NULL;
+       }
+
+       return ns;
+}
+
 static bool cmd_getacl(struct client_command_context *cmd)
 {
        struct mail_namespace *ns;
@@ -635,7 +655,7 @@ static bool cmd_getacl(struct client_command_context *cmd)
                return FALSE;
        orig_mailbox = mailbox;
 
-       ns = client_find_namespace(cmd, &mailbox);
+       ns = imap_acl_find_namespace(cmd, &mailbox);
        if (ns == NULL)
                return TRUE;
 
@@ -695,7 +715,7 @@ static bool cmd_myrights(struct client_command_context *cmd)
                return TRUE;
        }
 
-       ns = client_find_namespace(cmd, &mailbox);
+       ns = imap_acl_find_namespace(cmd, &mailbox);
        if (ns == NULL)
                return TRUE;
 
@@ -722,7 +742,7 @@ static bool cmd_listrights(struct client_command_context *cmd)
                return FALSE;
        orig_mailbox = mailbox;
 
-       ns = client_find_namespace(cmd, &mailbox);
+       ns = imap_acl_find_namespace(cmd, &mailbox);
        if (ns == NULL)
                return TRUE;
 
@@ -1007,7 +1027,7 @@ static bool cmd_setacl(struct client_command_context *cmd)
        /* Append original rights for proxy_cmd_args */
        imap_append_astring(proxy_cmd_args, rights);
 
-       ns = client_find_namespace(cmd, &mailbox);
+       ns = imap_acl_find_namespace(cmd, &mailbox);
        if (ns == NULL)
                return TRUE;
 
@@ -1068,7 +1088,7 @@ static bool cmd_deleteacl(struct client_command_context *cmd)
                return TRUE;
        }
 
-       ns = client_find_namespace(cmd, &mailbox);
+       ns = imap_acl_find_namespace(cmd, &mailbox);
        if (ns == NULL)
                return TRUE;