[PATCH 02/12] qemuDomainDiskPrivateDispose: Prevent dangling 'disk' pointer in blockjob data

Peter Krempa posted 12 patches 4 months ago
[PATCH 02/12] qemuDomainDiskPrivateDispose: Prevent dangling 'disk' pointer in blockjob data
Posted by Peter Krempa 4 months ago
Clear the 'disk' member of 'blockjob' as we're freeing the disk object
at this point. While this should not normally happen it was observed
when other bug allowed the VM to be cleared while other threads didn't
yet finish.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
---
 src/qemu/qemu_domain.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index 7ba2ea4a5e..a39f361a64 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -798,7 +798,13 @@ qemuDomainDiskPrivateDispose(void *obj)
     virObjectUnref(priv->migrSource);
     g_free(priv->qomName);
     g_free(priv->nodeCopyOnRead);
-    virObjectUnref(priv->blockjob);
+    if (priv->blockjob) {
+        /* Prevent dangling 'disk' pointer, as the disk object will be freed
+         * right after this function returns if any of the blockjob instance
+         * outlives this for any reason. */
+        priv->blockjob->disk = NULL;
+        virObjectUnref(priv->blockjob);
+    }
 }

 static virClass *qemuDomainStorageSourcePrivateClass;
-- 
2.45.2