Re: [PATCH 1/7] KVM: Grab a reference to KVM for VM and vCPU stats file descriptors

[Kees Cook]

On Tue, Jul 11, 2023 at 04:01:25PM -0700, Sean Christopherson wrote:
> Grab a reference to KVM prior to installing VM and vCPU stats file
> descriptors to ensure the underlying VM and vCPU objects are not freed
> until the last reference to any and all stats fds are dropped.
> 
> Note, the stats paths manually invoke fd_install() and so don't need to
> grab a reference before creating the file.
> 
> Fixes: ce55c049459c ("KVM: stats: Support binary stats retrieval for a VCPU")
> Fixes: fcfe1baeddbf ("KVM: stats: Support binary stats retrieval for a VM")
> Reported-by: Zheng Zhang <zheng.zhang@xxxxxxxxxxxxx>
> Closes: https://lore.kernel.org/all/CAC_GQSr3xzZaeZt85k_RCBd5kfiOve8qXo7a81Cq53LuVQ5r=Q@xxxxxxxxxxxxxx
> Cc: stable@xxxxxxxxxxxxxxx
> Cc: Kees Cook <keescook@xxxxxxxxxxxx>
> Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>

Thanks for preparing this! Looks like the common get/put code pattern,
so I can review this patch, unlike the rest of the series. :)

Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>

-- 
Kees Cook