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<p class="MsoPlainText"><span lang="EN-US">[PATCH] qemu: fix libvirtd crash in migration after vm shutdown<o:p></o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US">If we shutdown a guest, then migrate it without the arg XML, libvirtd will get crashed.<o:p></o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US">The reason is that: <o:p></o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US">1 during shutdown callback, qemuProcessStop() , it points vm->def to vm->newDef<o:p></o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US">2 during migration, it frees persistentDef, which points to vm->newDef when the arg XML is NULL.<o:p></o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US"> However, because vm->newDef is now vm->def, what we IN FACT freed is vm->def.<o:p></o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US">3 it will refer to vm->def after step2, thus invalid read/write causes libvirtd crash<o:p></o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US">We needn't to free persistentDef if persist_xml is NULL, because no extra def was alloced if persistent_xml is NULL.
<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">---<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">src/qemu/qemu_migration.c | 2 +-<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">1 file changed, 1 insertion(+), 1 deletion(-)<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">index 6a683f7..3636c93 100644<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">--- a/src/qemu/qemu_migration.c<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">+++ b/src/qemu/qemu_migration.c<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">@@ -4915,7 +4915,7 @@ qemuMigrationRun(virQEMUDriverPtr driver,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"> VIR_WARN("Unable to encode migration cookie");<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"> }<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">- if (persistDef != vm->newDef)<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">+ if (persist_xml && persistDef)<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"> virDomainDefFree(persistDef);<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"> qemuMigrationCookieFree(mig);<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">-- <o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">1.9.5.msysgit.1</span><span lang="EN-US"><o:p></o:p></span></p>
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