Commit d687ae1a authored by Markus Armbruster's avatar Markus Armbruster Committed by Cornelia Huck
Browse files

s390x/cpumodel: Fix realize() error API violations 



get_max_cpu_model() dereferences @errp when
kvm_s390_get_host_cpu_model() fails, apply_cpu_model() dereferences it
when kvm_s390_apply_cpu_model() fails, and s390_realize_cpu_model()
dereferences it when get_max_cpu_model() or check_compatibility()
fail.  That's wrong; see the big comment in error.h.  All three
introduced in commit 80560137 "s390x/cpumodel: check and apply the
CPU model".

No caller actually passes null.

Fix anyway: splice in a local Error *err, and error_propagate().

Cc: David Hildenbrand <david@redhat.com>
Cc: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: default avatarMarkus Armbruster <armbru@redhat.com>
Reviewed-by: default avatarDavid Hildenbrand <david@redhat.com>
Message-Id: <20191204093625.14836-14-armbru@redhat.com>
Signed-off-by: default avatarCornelia Huck <cohuck@redhat.com>
parent 0325e5a3

target/s390x/cpu_models.c

+22 −15
Original line number Diff line number Diff line
@@ -870,6 +870,7 @@ static void check_compatibility(const S390CPUModel *max_model, 


static S390CPUModel *get_max_cpu_model(Error **errp)

{

    Error *err = NULL;

    static S390CPUModel max_model;

    static bool cached;
@@ -878,22 +879,24 @@ static S390CPUModel *get_max_cpu_model(Error **errp) 
    }



    if (kvm_enabled()) {

        kvm_s390_get_host_cpu_model(&max_model, errp);

        kvm_s390_get_host_cpu_model(&max_model, &err);

    } else {

        max_model.def = s390_find_cpu_def(QEMU_MAX_CPU_TYPE, QEMU_MAX_CPU_GEN,

                                          QEMU_MAX_CPU_EC_GA, NULL);

        bitmap_copy(max_model.features, qemu_max_cpu_feat, S390_FEAT_MAX);

    }

    if (!*errp) {

    if (err) {

        error_propagate(errp, err);

        return NULL;

    }

    cached = true;

    return &max_model;

}

    return NULL;

}



static inline void apply_cpu_model(const S390CPUModel *model, Error **errp)

{

#ifndef CONFIG_USER_ONLY

    Error *err = NULL;

    static S390CPUModel applied_model;

    static bool applied;
@@ -909,20 +912,23 @@ static inline void apply_cpu_model(const S390CPUModel *model, Error **errp) 
    }



    if (kvm_enabled()) {

        kvm_s390_apply_cpu_model(model, errp);

        kvm_s390_apply_cpu_model(model, &err);

        if (err) {

            error_propagate(errp, err);

            return;

        }

    }



    if (!*errp) {

    applied = true;

    if (model) {

        applied_model = *model;

    }

    }

#endif

}



void s390_realize_cpu_model(CPUState *cs, Error **errp)

{

    Error *err = NULL;

    S390CPUClass *xcc = S390_CPU_GET_CLASS(cs);

    S390CPU *cpu = S390_CPU(cs);

    const S390CPUModel *max_model;
@@ -939,7 +945,7 @@ void s390_realize_cpu_model(CPUState *cs, Error **errp) 
    }



    max_model = get_max_cpu_model(errp);

    if (*errp) {

    if (!max_model) {

        error_prepend(errp, "CPU models are not available: ");

        return;

    }
@@ -951,8 +957,9 @@ void s390_realize_cpu_model(CPUState *cs, Error **errp) 
    cpu->model->cpu_ver = max_model->cpu_ver;



    check_consistency(cpu->model);

    check_compatibility(max_model, cpu->model, errp);

    if (*errp) {

    check_compatibility(max_model, cpu->model, &err);

    if (err) {

        error_propagate(errp, err);

        return;

    }