1 files changed, 1 insertions, 1 deletions
diff --git a/hw/ide/ahci.c b/hw/ide/ahci.c
index ee1d47f..680304a 100644
--- a/hw/ide/ahci.c
+++ b/hw/ide/ahci.c
@@ -250,7 +250,7 @@ static void map_page(AddressSpace *as, uint8_t **ptr, uint64_t addr,
     }
 
     *ptr = dma_memory_map(as, addr, &len, DMA_DIRECTION_FROM_DEVICE);
-    if (len < wanted) {
+    if (len < wanted && *ptr) {
         dma_memory_unmap(as, *ptr, len, DMA_DIRECTION_FROM_DEVICE, len);
         *ptr = NULL;
     }