Blame SOURCES/kvm-i386-Fix-arch_query_cpu_model_expansion-leak.patch

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From 03f6fac8ac03d391fdbd7353ffd7c6eb1bd30bea Mon Sep 17 00:00:00 2001
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From: Markus Armbruster <armbru@redhat.com>
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Date: Fri, 31 Aug 2018 13:59:22 +0100
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Subject: [PATCH 2/3] i386: Fix arch_query_cpu_model_expansion() leak
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RH-Author: Markus Armbruster <armbru@redhat.com>
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Message-id: <20180831135922.6073-3-armbru@redhat.com>
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Patchwork-id: 81980
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O-Subject: [qemu-kvm RHEL8/virt212 PATCH 2/2] i386: Fix arch_query_cpu_model_expansion() leak
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Bugzilla: 1615717
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RH-Acked-by: Eduardo Habkost <ehabkost@redhat.com>
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RH-Acked-by: Laszlo Ersek <lersek@redhat.com>
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RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
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From: Eduardo Habkost <ehabkost@redhat.com>
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Reported by Coverity:
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Error: RESOURCE_LEAK (CWE-772): [#def439]
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qemu-2.12.0/target/i386/cpu.c:3179: alloc_fn: Storage is returned from allocation function "qdict_new".
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qemu-2.12.0/qobject/qdict.c:34:5: alloc_fn: Storage is returned from allocation function "g_malloc0".
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qemu-2.12.0/qobject/qdict.c:34:5: var_assign: Assigning: "qdict" = "g_malloc0(4120UL)".
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qemu-2.12.0/qobject/qdict.c:37:5: return_alloc: Returning allocated memory "qdict".
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qemu-2.12.0/target/i386/cpu.c:3179: var_assign: Assigning: "props" = storage returned from "qdict_new()".
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qemu-2.12.0/target/i386/cpu.c:3217: leaked_storage: Variable "props" going out of scope leaks the storage it points to.
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This was introduced by commit b8097deb359b ("i386: Improve
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query-cpu-model-expansion full mode").
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The leak is only theoretical: if ret->model->props is set to
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props, the qapi_free_CpuModelExpansionInfo() call will free props
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too in case of errors.  The only way for this to not happen is if
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we enter the default branch of the switch statement, which would
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never happen because all CpuModelExpansionType values are being
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handled.
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It's still worth to change this to make the allocation logic
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easier to follow and make the Coverity error go away.  To make
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everything simpler, initialize ret->model and ret->model->props
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earlier in the function.
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While at it, remove redundant check for !prop because prop is
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always initialized at the beginning of the function.
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Fixes: b8097deb359bbbd92592b9670adfe9e245b2d0bd
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Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
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Message-Id: <20180816183509.8231-1-ehabkost@redhat.com>
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Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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(cherry picked from commit e38bf612477fca62b205ebd909b1372a7e45a8c0)
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Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>
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---
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 target/i386/cpu.c | 9 +++------
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 1 file changed, 3 insertions(+), 6 deletions(-)
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diff --git a/target/i386/cpu.c b/target/i386/cpu.c
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index caab4e2..605d0fa 100644
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--- a/target/i386/cpu.c
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+++ b/target/i386/cpu.c
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@@ -3727,6 +3727,9 @@ arch_query_cpu_model_expansion(CpuModelExpansionType type,
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     }
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     props = qdict_new();
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+    ret->model = g_new0(CpuModelInfo, 1);
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+    ret->model->props = QOBJECT(props);
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+    ret->model->has_props = true;
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     switch (type) {
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     case CPU_MODEL_EXPANSION_TYPE_STATIC:
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@@ -3747,15 +3750,9 @@ arch_query_cpu_model_expansion(CpuModelExpansionType type,
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         goto out;
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     }
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-    if (!props) {
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-        props = qdict_new();
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-    }
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     x86_cpu_to_dict(xc, props);
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-    ret->model = g_new0(CpuModelInfo, 1);
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     ret->model->name = g_strdup(base_name);
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-    ret->model->props = QOBJECT(props);
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-    ret->model->has_props = true;
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 out:
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     object_unref(OBJECT(xc));
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-- 
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1.8.3.1
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