[PATCH 08/10] dm-ima: Handle race between rename and table swap

[Benjamin Marzinski <bmarzins@redhat.com>]

a device rename could happen after do_resume() removed the inactive
table that it was swapping to out of the hash cell, but before it was
made the active table. In this case, the table metadata would still
have the old name. Update the swapped table's metadata to avoid this.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
---
 drivers/md/dm-ima.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/md/dm-ima.c b/drivers/md/dm-ima.c
index 5c6f3f8761a8..4631dc2a6d4d 100644
--- a/drivers/md/dm-ima.c
+++ b/drivers/md/dm-ima.c
@@ -367,6 +367,19 @@ void dm_ima_measure_on_device_resume(struct mapped_device *md, bool swap,
 		kfree(md->ima.active_table.device_metadata);
 		md->ima.active_table = context->table;
 		memset(&context->table, 0, sizeof(context->table));
+		if (md->ima.active_table.device_metadata) {
+			/*
+			 * A rename could have happened while the swap was
+			 * going on. In that case, the saved table info would
+			 * still have the old name. Update the metadata to be
+			 * sure that it has the current name
+			 */
+			struct dm_ima_device_table_metadata *table = &md->ima.active_table;
+			fix_context_strings(context);
+			dm_ima_copy_device_data(md, table->device_metadata,
+						context, table->num_targets);
+			table->device_metadata_len = strlen(table->device_metadata);
+		}
 	}
 
 	if (md->ima.active_table.device_metadata) {
-- 
2.53.0