[Qemu-devel] [PATCH v2 2/2] memory: fix possible NULL pointer dereference

[Dima Stepanov]

In the memory_region_do_invalidate_mmio_ptr() routine the section
variable is intialized by the memory_region_find() call. The section.mr
field can be set to NULL.

Add the check for NULL before trying to drop a section.

Signed-off-by: Dima Stepanov <address@hidden>
---
 memory.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/memory.c b/memory.c
index 3212acc..bb45248 100644
--- a/memory.c
+++ b/memory.c
@@ -2712,7 +2712,7 @@ static void memory_region_do_invalidate_mmio_ptr(CPUState 
*cpu,
     /* Reset dirty so this doesn't happen later. */
     cpu_physical_memory_test_and_clear_dirty(offset, size, 1);
 
-    if (section.mr != mr) {
+    if (section.mr && (section.mr != mr)) {
         /* memory_region_find add a ref on section.mr */
         memory_region_unref(section.mr);
         if (MMIO_INTERFACE(section.mr->owner)) {
-- 
2.7.4