diff --git a/block/qcow.c b/block/qcow.c
index 66827d6f24158cae4366ad9eb487d831da98c93e..c08cdc4a7b9b62312f80da9ce55462ecfaa3b6de 100644
--- a/block/qcow.c
+++ b/block/qcow.c
@@ -768,7 +768,7 @@ static int qcow_create(const char *filename, QemuOpts *opts, Error **errp)
     Error *local_err = NULL;
     int ret;
     BlockBackend *qcow_blk;
-    const char *encryptfmt = NULL;
+    char *encryptfmt = NULL;
     QDict *options;
     QDict *encryptopts = NULL;
     QCryptoBlockCreateOptions *crypto_opts = NULL;
@@ -793,7 +793,7 @@ static int qcow_create(const char *filename, QemuOpts *opts, Error **errp)
             goto cleanup;
         }
     } else if (qemu_opt_get_bool_del(opts, BLOCK_OPT_ENCRYPT, false)) {
-        encryptfmt = "aes";
+        encryptfmt = g_strdup("aes");
     }
 
     ret = bdrv_create_file(filename, opts, &local_err);
@@ -908,6 +908,7 @@ exit:
     blk_unref(qcow_blk);
 cleanup:
     QDECREF(encryptopts);
+    g_free(encryptfmt);
     qcrypto_block_free(crypto);
     qapi_free_QCryptoBlockCreateOptions(crypto_opts);
     g_free(backing_file);
diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c
index 3e8735a20d4861018920c4a3d3e659f53b8a67e0..e8d3bdbd6eaf9dd73a5ef6a007a2f4e6f95117d4 100644
--- a/block/qcow2-bitmap.c
+++ b/block/qcow2-bitmap.c
@@ -487,6 +487,10 @@ static inline void bitmap_directory_to_be(uint8_t *dir, size_t size)
 
 static void bitmap_free(Qcow2Bitmap *bm)
 {
+    if (bm == NULL) {
+        return;
+    }
+
     g_free(bm->name);
     g_free(bm);
 }
diff --git a/block/qcow2.c b/block/qcow2.c
index 90efa4477b3134e0502c035c085c17272ef253db..d7c600b5a228bbcc494352318fad98fa1e04067f 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -2905,7 +2905,7 @@ static int qcow2_create(const char *filename, QemuOpts *opts, Error **errp)
     int version;
     uint64_t refcount_bits;
     int refcount_order;
-    const char *encryptfmt = NULL;
+    char *encryptfmt = NULL;
     Error *local_err = NULL;
     int ret;
 
@@ -2916,14 +2916,14 @@ static int qcow2_create(const char *filename, QemuOpts *opts, Error **errp)
     backing_fmt = qemu_opt_get_del(opts, BLOCK_OPT_BACKING_FMT);
     encryptfmt = qemu_opt_get_del(opts, BLOCK_OPT_ENCRYPT_FORMAT);
     if (encryptfmt) {
-        if (qemu_opt_get_del(opts, BLOCK_OPT_ENCRYPT)) {
+        if (qemu_opt_get(opts, BLOCK_OPT_ENCRYPT)) {
             error_setg(errp, "Options " BLOCK_OPT_ENCRYPT " and "
                        BLOCK_OPT_ENCRYPT_FORMAT " are mutually exclusive");
             ret = -EINVAL;
             goto finish;
         }
     } else if (qemu_opt_get_bool_del(opts, BLOCK_OPT_ENCRYPT, false)) {
-        encryptfmt = "aes";
+        encryptfmt = g_strdup("aes");
     }
     cluster_size = qcow2_opt_get_cluster_size_del(opts, &local_err);
     if (local_err) {
@@ -2983,6 +2983,7 @@ static int qcow2_create(const char *filename, QemuOpts *opts, Error **errp)
 finish:
     g_free(backing_file);
     g_free(backing_fmt);
+    g_free(encryptfmt);
     g_free(buf);
     return ret;
 }
diff --git a/tests/qemu-iotests/186.out b/tests/qemu-iotests/186.out
index b963b12d64b6e24bfbb3b45fa68c87e0fff9f9b9..b8bf9a25500fbcbf53c26d6510382a23f1f4c096 100644
--- a/tests/qemu-iotests/186.out
+++ b/tests/qemu-iotests/186.out
@@ -442,7 +442,7 @@ ide0-cd0 (NODE_NAME): null-co:// (null-co, read-only)
     Cache mode:       writeback
 (qemu) quit
 
-warning: qemu-system-x86_64: -drive if=scsi,driver=null-co: bus=0,unit=0 is deprecated with this machine type
+qemu-system-x86_64: -drive if=scsi,driver=null-co: warning: bus=0,unit=0 is deprecated with this machine type
 Testing: -drive if=scsi,driver=null-co
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) info block
@@ -451,7 +451,7 @@ scsi0-hd0 (NODE_NAME): null-co:// (null-co)
     Cache mode:       writeback
 (qemu) quit
 
-warning: qemu-system-x86_64: -drive if=scsi,media=cdrom: bus=0,unit=0 is deprecated with this machine type
+qemu-system-x86_64: -drive if=scsi,media=cdrom: warning: bus=0,unit=0 is deprecated with this machine type
 Testing: -drive if=scsi,media=cdrom
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) info block
@@ -460,7 +460,7 @@ scsi0-cd0: [not inserted]
     Removable device: not locked, tray closed
 (qemu) quit
 
-warning: qemu-system-x86_64: -drive if=scsi,driver=null-co,media=cdrom: bus=0,unit=0 is deprecated with this machine type
+qemu-system-x86_64: -drive if=scsi,driver=null-co,media=cdrom: warning: bus=0,unit=0 is deprecated with this machine type
 Testing: -drive if=scsi,driver=null-co,media=cdrom
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) info block