Add basic metadata integrity check. In case when partition table was

probed and read successfull, but it contains invalid values (e.g.
overlapped partitions, offset or size is out of bounds), then table
will be rejected.

MFC after:	1 month

1 files changed, 48 insertions, 1 deletions

diff --git a/sys/geom/part/g_part.c b/sys/geom/part/g_part.c
index 437914a..aa5444e 100644
--- a/sys/geom/part/g_part.c
+++ b/sys/geom/part/g_part.c
@@ -231,6 +231,48 @@ g_part_geometry(struct g_part_table *table, struct g_consumer *cp,
 	}
 }
 
+static int
+g_part_check_integrity(struct g_part_table *table, struct g_consumer *cp)
+{
+	struct g_part_entry *e1, *e2;
+	struct g_provider *pp;
+
+	pp = cp->provider;
+	if (table->gpt_first > table->gpt_last ||
+	    table->gpt_last > pp->mediasize / pp->sectorsize - 1)
+		goto fail;
+
+	LIST_FOREACH(e1, &table->gpt_entry, gpe_entry) {
+		if (e1->gpe_deleted || e1->gpe_internal)
+			continue;
+		if (e1->gpe_start < table->gpt_first ||
+		    e1->gpe_start > table->gpt_last ||
+		    e1->gpe_end < e1->gpe_start ||
+		    e1->gpe_end > table->gpt_last)
+			goto fail;
+		e2 = e1;
+		while ((e2 = LIST_NEXT(e2, gpe_entry)) != NULL) {
+			if (e2->gpe_deleted || e2->gpe_internal)
+				continue;
+			if (e1->gpe_start >= e2->gpe_start &&
+			    e1->gpe_start <= e2->gpe_end)
+				goto fail;
+			if (e1->gpe_end >= e2->gpe_start &&
+			    e1->gpe_end <= e2->gpe_end)
+				goto fail;
+			if (e1->gpe_start < e2->gpe_start &&
+			    e1->gpe_end > e2->gpe_end)
+				goto fail;
+		}
+	}
+	return (0);
+fail:
+	if (bootverbose)
+		printf("GEOM_PART: integrity check failed (%s, %s)\n",
+		    pp->name, table->gpt_scheme->name);
+	return (EINVAL);
+}
+
 struct g_part_entry *
 g_part_new_entry(struct g_part_table *table, int index, quad_t start,
     quad_t end)
@@ -1310,9 +1352,11 @@ g_part_ctl_undo(struct gctl_req *req, struct g_part_parms *gpp)
 	error = G_PART_READ(table, cp);
 	if (error)
 		goto fail;
+	error = g_part_check_integrity(table, cp);
+	if (error)
+		goto fail;
 
 	g_topology_lock();
-
 	LIST_FOREACH(entry, &table->gpt_entry, gpe_entry) {
 		if (!entry->gpe_internal)
 			g_part_new_provider(gp, table, entry);
@@ -1773,6 +1817,9 @@ g_part_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
 	error = G_PART_READ(table, cp);
 	if (error)
 		goto fail;
+	error = g_part_check_integrity(table, cp);
+	if (error)
+		goto fail;
 
 	g_topology_lock();
 	LIST_FOREACH(entry, &table->gpt_entry, gpe_entry) {