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[Qemu-devel] [PATCH 3/3] memory: keep the owner of the AddressSpace aliv
From: |
Paolo Bonzini |
Subject: |
[Qemu-devel] [PATCH 3/3] memory: keep the owner of the AddressSpace alive until do_address_space_destroy |
Date: |
Wed, 11 Feb 2015 18:14:32 +0100 |
This fixes a use-after-free if do_address_space_destroy is executed
too late.
Signed-off-by: Paolo Bonzini <address@hidden>
---
memory.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/memory.c b/memory.c
index 130152c..20f6d9e 100644
--- a/memory.c
+++ b/memory.c
@@ -1943,6 +1943,7 @@ void memory_listener_unregister(MemoryListener *listener)
void address_space_init(AddressSpace *as, MemoryRegion *root, const char *name)
{
+ memory_region_ref(root);
memory_region_transaction_begin();
as->root = root;
as->current_map = g_new(FlatView, 1);
@@ -1969,10 +1970,13 @@ static void do_address_space_destroy(AddressSpace *as)
flatview_unref(as->current_map);
g_free(as->name);
g_free(as->ioeventfds);
+ memory_region_unref(as->root);
}
void address_space_destroy(AddressSpace *as)
{
+ MemoryRegion *root = as->root;
+
/* Flush out anything from MemoryListeners listening in on this */
memory_region_transaction_begin();
as->root = NULL;
@@ -1984,6 +1988,7 @@ void address_space_destroy(AddressSpace *as)
* entries that the guest should never use. Wait for the old
* values to expire before freeing the data.
*/
+ as->root = root;
call_rcu(as, do_address_space_destroy, rcu);
}
--
1.8.3.1