From e38bf612477fca62b205ebd909b1372a7e45a8c0 Mon Sep 17 00:00:00 2001 From: Eduardo Habkost Date: Thu, 16 Aug 2018 15:35:09 -0300 Subject: [PATCH] i386: Fix arch_query_cpu_model_expansion() leak Reported by Coverity: Error: RESOURCE_LEAK (CWE-772): [#def439] qemu-2.12.0/target/i386/cpu.c:3179: alloc_fn: Storage is returned from allocation function "qdict_new". qemu-2.12.0/qobject/qdict.c:34:5: alloc_fn: Storage is returned from allocation function "g_malloc0". qemu-2.12.0/qobject/qdict.c:34:5: var_assign: Assigning: "qdict" = "g_malloc0(4120UL)". qemu-2.12.0/qobject/qdict.c:37:5: return_alloc: Returning allocated memory "qdict". qemu-2.12.0/target/i386/cpu.c:3179: var_assign: Assigning: "props" = storage returned from "qdict_new()". qemu-2.12.0/target/i386/cpu.c:3217: leaked_storage: Variable "props" going out of scope leaks the storage it points to. This was introduced by commit b8097deb359b ("i386: Improve query-cpu-model-expansion full mode"). The leak is only theoretical: if ret->model->props is set to props, the qapi_free_CpuModelExpansionInfo() call will free props too in case of errors. The only way for this to not happen is if we enter the default branch of the switch statement, which would never happen because all CpuModelExpansionType values are being handled. It's still worth to change this to make the allocation logic easier to follow and make the Coverity error go away. To make everything simpler, initialize ret->model and ret->model->props earlier in the function. While at it, remove redundant check for !prop because prop is always initialized at the beginning of the function. Fixes: b8097deb359bbbd92592b9670adfe9e245b2d0bd Signed-off-by: Eduardo Habkost Message-Id: <20180816183509.8231-1-ehabkost@redhat.com> Signed-off-by: Paolo Bonzini --- target/i386/cpu.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 4e4fe8fa8b..f24295e6e4 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -3880,6 +3880,9 @@ arch_query_cpu_model_expansion(CpuModelExpansionType type, } props = qdict_new(); + ret->model = g_new0(CpuModelInfo, 1); + ret->model->props = QOBJECT(props); + ret->model->has_props = true; switch (type) { case CPU_MODEL_EXPANSION_TYPE_STATIC: @@ -3900,15 +3903,9 @@ arch_query_cpu_model_expansion(CpuModelExpansionType type, goto out; } - if (!props) { - props = qdict_new(); - } x86_cpu_to_dict(xc, props); - ret->model = g_new0(CpuModelInfo, 1); ret->model->name = g_strdup(base_name); - ret->model->props = QOBJECT(props); - ret->model->has_props = true; out: object_unref(OBJECT(xc)); -- 2.39.2