autofs-5.1.7 - check for offset with no mount location

From: Ian Kent <raven@themaw.net>

Offsets need to have a mount location, check for it.

Signed-off-by: Ian Kent <raven@themaw.net>
---
 CHANGELOG           |    1 +
 modules/parse_sun.c |   15 ++++++++++++++-
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG b/CHANGELOG
index a9209755..42914160 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -47,6 +47,7 @@
 - pass root length to mount_fullpath().
 - remove unused function master_submount_list_empty().
 - move amd mounts removal into lib/mounts.c.
+- check for offset with no mount location.
 
 25/01/2021 autofs-5.1.7
 - make bind mounts propagation slave by default.
diff --git a/modules/parse_sun.c b/modules/parse_sun.c
index b1c2611c..a81d4028 100644
--- a/modules/parse_sun.c
+++ b/modules/parse_sun.c
@@ -801,7 +801,20 @@ update_offset_entry(struct autofs_point *ap,
 
 	memset(m_mapent, 0, MAPENT_MAX_LEN + 1);
 
-	/* Internal hosts map may have loc == NULL */
+	if (!loc || !*loc) {
+		const char *type = ap->entry->maps->type;
+
+		/* If it's not the internal hosts map it must have a
+		 * mount location.
+		 */
+		if (!type || strcmp(type, "hosts")) {
+			error(ap->logopt,
+			      MODPREFIX "syntax error in offset %s -> %s",
+			      m_offset, loc);
+			return CHE_FAIL;
+		}
+	}
+
 	if (!*m_offset) {
 		error(ap->logopt,
 		      MODPREFIX "syntax error in offset %s -> %s", m_offset, loc);