MdeModulePkg/Bus/Pci/UhciDxe: Fix FORWARD_NULL Coverity issues

The function UsbHcGetPciAddressForHostMem has ASSERT ((Block != NULL)); and and the function UsbHcFreeMem has ASSERT (Block != NULL); statement after for loop, but these are applicable only in DEBUG mode. In RELEASE mode, if for whatever reasons there is no match inside for loop and the loop exits because of Block != NULL; condition, then there is no "Block" NULL pointer check afterwards and the code proceeds to do dereferencing "Block" which will lead to CRASH. Hence, for safety add NULL pointer checks always. REF: https://bugzilla.tianocore.org/show_bug.cgi?id=4211 Cc: Hao A Wu <[email protected]> Cc: Ray Ni <[email protected]> Co-authored-by: Veeresh Sangolli <[email protected]> Signed-off-by: Ranbir Singh <[email protected]> Signed-off-by: Ranbir Singh <[email protected]> Reviewed-by: Hao A Wu <[email protected]>
coreboot · Sep 22, 2023 · 28a267a · 28a267a
1 parent e9f5d8c
commit 28a267a
Showing 1 changed file with 9 additions and 0 deletions.
diff --git a/MdeModulePkg/Bus/Pci/UhciDxe/UsbHcMem.c b/MdeModulePkg/Bus/Pci/UhciDxe/UsbHcMem.c
@@ -250,6 +250,11 @@ UsbHcGetPciAddressForHostMem (
   }
 
   ASSERT ((Block != NULL));
+
+  if (Block == NULL) {
+    return 0;
+  }
+
   //
   // calculate the pci memory address for host memory address.
   //
@@ -536,6 +541,10 @@ UsbHcFreeMem (
   //
   ASSERT (Block != NULL);
 
+  if (Block == NULL) {
+    return;
+  }
+
   //
   // Release the current memory block if it is empty and not the head
   //