autofs-5.1.9 - initialise fields after free in clear_amd_entry()

From: Ian Kent <raven@themaw.net>

Avoid potential use after free bugs by reinitialising fields that are
freed in clear_amd_entry().

Signed-off-by: Ian Kent <raven@themaw.net>
---
 CHANGELOG    |    1 +
 lib/mounts.c |   60 ++++++++++++++++++++++++++++++++++++++++++++--------------
 2 files changed, 46 insertions(+), 15 deletions(-)

diff --git a/CHANGELOG b/CHANGELOG
index 65090c0f5..a23645139 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -84,6 +84,7 @@
 - skip expire check for amd nounmount mounts.
 - Fix masks in parse_sub.c, so that hosts are correctly matched.
 - fix fields not freed in clear_amd_entry().
+- initialise fields after free in clear_amd_entry().
 
 02/11/2023 autofs-5.1.9
 - fix kernel mount status notification.
diff --git a/lib/mounts.c b/lib/mounts.c
index effedc631..8905cedb8 100644
--- a/lib/mounts.c
+++ b/lib/mounts.c
@@ -643,36 +643,66 @@ void clear_amd_entry(struct amd_entry *entry)
 {
 	if (!entry)
 		return;
-	if (entry->path)
+	if (entry->path) {
 		free(entry->path);
-	if (entry->type)
+		entry->path = NULL;
+	}
+	if (entry->type) {
 		free(entry->type);
-	if (entry->map_type)
+		entry->type = NULL;
+	}
+	if (entry->map_type) {
 		free(entry->map_type);
-	if (entry->pref)
+		entry->map_type = NULL;
+	}
+	if (entry->pref) {
 		free(entry->pref);
-	if (entry->fs)
+		entry->pref = NULL;
+	}
+	if (entry->fs) {
 		free(entry->fs);
-	if (entry->rhost)
+		entry->fs = NULL;
+	}
+	if (entry->rhost) {
 		free(entry->rhost);
-	if (entry->rfs)
+		entry->rhost = NULL;
+	}
+	if (entry->rfs) {
 		free(entry->rfs);
-	if (entry->dev)
+		entry->rfs = NULL;
+	}
+	if (entry->dev) {
 		free(entry->dev);
-	if (entry->opts)
+		entry->dev = NULL;
+	}
+	if (entry->opts) {
 		free(entry->opts);
-	if (entry->addopts)
+		entry->opts = NULL;
+	}
+	if (entry->addopts) {
 		free(entry->addopts);
-	if (entry->remopts)
+		entry->addopts = NULL;
+	}
+	if (entry->remopts) {
 		free(entry->remopts);
-	if (entry->sublink)
+		entry->remopts = NULL;
+	}
+	if (entry->sublink) {
 		free(entry->sublink);
-	if (entry->mount)
+		entry->sublink = NULL;
+	}
+	if (entry->mount) {
 		free(entry->mount);
-	if (entry->umount)
+		entry->mount = NULL;
+	}
+	if (entry->umount) {
 		free(entry->umount);
-	if (entry->selector)
+		entry->umount = NULL;
+	}
+	if (entry->selector) {
 		free_selector(entry->selector);
+		entry->selector = NULL;
+	}
 	return;
 }