From: Peter Krempa <pkrempa@redhat.com>
Date: Tue, 11 Jun 2024 13:50:52 +0000 (+0200)
Subject: qemuDomainDiskPrivateDispose: Prevent dangling 'disk' pointer in blockjob data
X-Git-Tag: v10.5.0-rc1~40
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=b4423a753baa46993c4215a0f7480725b205bf44;p=thirdparty%2Flibvirt.git

qemuDomainDiskPrivateDispose: Prevent dangling 'disk' pointer in blockjob data

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>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
---

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;