Re: [PATCH tip] KVM: nSVM: avoid freeing uninitialized pointers in svm_set_nested_state()

From: Sean Christopherson
Date: Mon Sep 14 2020 - 11:11:23 EST


On Mon, Sep 14, 2020 at 03:37:25PM +0200, Vitaly Kuznetsov wrote:
> The save and ctl pointers are passed uninitialized to kfree() when
> svm_set_nested_state() follows the 'goto out_set_gif' path. While
> the issue could've been fixed by initializing these on-stack varialbles
> to NULL, it seems preferable to eliminate 'out_set_gif' label completely
> as it is not actually a failure path and duplicating a single svm_set_gif()
> call doesn't look too bad.
>
> Fixes: 6ccbd29ade0d ("KVM: SVM: nested: Don't allocate VMCB structures on stack")
> Addresses-Coverity: ("Uninitialized pointer read")
> Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> Reported-by: Joerg Roedel <jroedel@xxxxxxx>
> Reported-by: Colin King <colin.king@xxxxxxxxxxxxx>
> Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
> ---

Reviewed-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>