[Qemu-block] [PATCH 1/4] ahci: Do not unmap NULL addresses

[John Snow]

Definitely don't try to unmap a garbage address.

Reported-by: Zuozhi fzz <address@hidden>
Signed-off-by: John Snow <address@hidden>
---
 hw/ide/ahci.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/hw/ide/ahci.c b/hw/ide/ahci.c
index 17f1cbd..cdc9299 100644
--- a/hw/ide/ahci.c
+++ b/hw/ide/ahci.c
@@ -661,6 +661,10 @@ static bool ahci_map_fis_address(AHCIDevice *ad)
 
 static void ahci_unmap_fis_address(AHCIDevice *ad)
 {
+    if (ad->res_fis == NULL) {
+        DPRINTF(ad->port_no, "Attempt to unmap NULL FIS address\n");
+        return;
+    }
     dma_memory_unmap(ad->hba->as, ad->res_fis, 256,
                      DMA_DIRECTION_FROM_DEVICE, 256);
     ad->res_fis = NULL;
@@ -677,6 +681,10 @@ static bool ahci_map_clb_address(AHCIDevice *ad)
 
 static void ahci_unmap_clb_address(AHCIDevice *ad)
 {
+    if (ad->lst == NULL) {
+        DPRINTF(ad->port_no, "Attempt to unmap NULL CLB address\n");
+        return;
+    }
     dma_memory_unmap(ad->hba->as, ad->lst, 1024,
                      DMA_DIRECTION_FROM_DEVICE, 1024);
     ad->lst = NULL;
-- 
2.4.3