diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c
index 98eff1259de4d..0150570c33aae 100644
--- a/fs/erofs/zmap.c
+++ b/fs/erofs/zmap.c
@@ -698,6 +698,11 @@ static int z_erofs_do_map_blocks(struct inode *inode,
 	}
 
 	if (m.headtype == Z_EROFS_VLE_CLUSTER_TYPE_PLAIN) {
+		if (map->m_llen > map->m_plen) {
+			DBG_BUGON(1);
+			err = -EFSCORRUPTED;
+			goto unmap_out;
+		}
 		if (vi->z_advise & Z_EROFS_ADVISE_INTERLACED_PCLUSTER)
 			map->m_algorithmformat =
 				Z_EROFS_COMPRESSION_INTERLACED;