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

[Tom Lendacky]

On 9/14/20 8:37 AM, 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>

Tested-by: Tom Lendacky <thomas.lendacky@xxxxxxx>