dm vdo: return error on corrupted metadata in start_restoring_volume functions

JIRA: https://issues.redhat.com/browse/RHEL-119008
Upstream Status: kernel/git/torvalds/linux.git

commit 9ddf6d3
Author: Ivan Abramov <i.abramov@mt-integration.ru>
Date:   Tue Sep 9 23:22:38 2025 +0300

    dm vdo: return error on corrupted metadata in start_restoring_volume functions

    The return values of VDO_ASSERT calls that validate metadata are not acted
    upon.

    Return UDS_CORRUPT_DATA in case of an error.

    Found by Linux Verification Center (linuxtesting.org) with SVACE.

    Fixes: a4eb7e2 ("dm vdo: implement the volume index")
    Signed-off-by: Ivan Abramov <i.abramov@mt-integration.ru>
    Reviewed-by: Matthew Sakai <msakai@redhat.com>
    Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>

Author: bmarzins

drivers/md/dm-vdo/indexer/volume-index.c

@@ -836,7 +836,7 @@ static int start_restoring_volume_sub_index(struct volume_sub_index *sub_index,
 				    "%zu bytes decoded of %zu expected", offset,
 				    sizeof(buffer));
 		if (result != VDO_SUCCESS)
-			result = UDS_CORRUPT_DATA;
+			return UDS_CORRUPT_DATA;
 
 		if (memcmp(header.magic, MAGIC_START_5, MAGIC_SIZE) != 0) {
 			return vdo_log_warning_strerror(UDS_CORRUPT_DATA,
@@ -928,7 +928,7 @@ static int start_restoring_volume_index(struct volume_index *volume_index,
 				    "%zu bytes decoded of %zu expected", offset,
 				    sizeof(buffer));
 		if (result != VDO_SUCCESS)
-			result = UDS_CORRUPT_DATA;
+			return UDS_CORRUPT_DATA;
 
 		if (memcmp(header.magic, MAGIC_START_6, MAGIC_SIZE) != 0)
 			return vdo_log_warning_strerror(UDS_CORRUPT_DATA,