[PATCH v2 1/4] powerpc/kvm/book3s: Fixes possible 'use after release' of kvm

[Leonardo Bras]

Fixes a possible 'use after free' of kvm variable in
kvm_vm_ioctl_create_spapr_tce, where it does a mutex_unlock(&kvm->lock)
after a kvm_put_kvm(kvm).

Signed-off-by: Leonardo Bras <leona...@linux.ibm.com>
---
 arch/powerpc/kvm/book3s_64_vio.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_64_vio.c b/arch/powerpc/kvm/book3s_64_vio.c
index 5834db0a54c6..a402ead833b6 100644
--- a/arch/powerpc/kvm/book3s_64_vio.c
+++ b/arch/powerpc/kvm/book3s_64_vio.c
@@ -316,14 +316,13 @@ long kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm,
 
        if (ret >= 0)
                list_add_rcu(&stt->list, &kvm->arch.spapr_tce_tables);
-       else
-               kvm_put_kvm(kvm);
 
        mutex_unlock(&kvm->lock);
 
        if (ret >= 0)
                return ret;
 
+       kvm_put_kvm(kvm);
        kfree(stt);
  fail_acct:
        account_locked_vm(current->mm, kvmppc_stt_pages(npages), false);
-- 
2.23.0