added memory unhooking error checking to fix CGA deinit crash

[palacios.git] / palacios / src / palacios / vmm_mem_hook.c

diff --git a/palacios/src/palacios/vmm_mem_hook.c b/palacios/src/palacios/vmm_mem_hook.c
index ee632b0..a0753cf 100644 (file)
--- a/palacios/src/palacios/vmm_mem_hook.c
+++ b/palacios/src/palacios/vmm_mem_hook.c
@@ -135,7 +135,7 @@ static int handle_mem_hook(struct guest_info * core, addr_t guest_va, addr_t gue
     }
 
     if (ret == -1) {
-       PrintError("Could not translate Instruction Address (%p)\n", (void *)core->rip);
+      PrintError("Could not translate Instruction Address (%p)\n", (void *)(addr_t)core->rip);
        return -1;
     }
 
@@ -394,7 +394,20 @@ static int free_hook(struct v3_vm_info * vm, struct mem_hook * hook) {
 // We do not support unhooking subregions
 int v3_unhook_mem(struct v3_vm_info * vm, uint16_t core_id, addr_t guest_addr_start) {
     struct v3_mem_region * reg = v3_get_mem_region(vm, core_id, guest_addr_start);
-    struct mem_hook * hook = reg->priv_data;
+    struct mem_hook * hook = NULL;
+
+    if (reg == NULL) {
+       PrintError("Could not find region at %p\n", (void *)guest_addr_start);
+       return -1;
+    }
+
+    hook = reg->priv_data;
+
+    if (hook == NULL) {
+       PrintError("Trying to unhook region that is not a hook at %p\n", (void *)guest_addr_start);
+       return -1;
+    }
+
 
     free_hook(vm, hook);