Re: FAILED: patch "[PATCH] KVM: VMX: Don't use vcpu->run->internal.ndata as an array" failed to apply to 5.11-stable tree

[Sasha Levin <sashal@kernel.org>]

On Sun, Apr 18, 2021 at 12:34:36PM +0200, gregkh@linuxfoundation.org wrote:
>
>The patch below does not apply to the 5.11-stable tree.
>If someone wants it applied there, or to any other stable or longterm
>tree, then please email the backport, including the original git commit
>id to <stable@vger.kernel.org>.
>
>thanks,
>
>greg k-h
>
>------------------ original commit in Linus's tree ------------------
>
>From 04c4f2ee3f68c9a4bf1653d15f1a9a435ae33f7a Mon Sep 17 00:00:00 2001
>From: Reiji Watanabe <reijiw@google.com>
>Date: Tue, 13 Apr 2021 15:47:40 +0000
>Subject: [PATCH] KVM: VMX: Don't use vcpu->run->internal.ndata as an array
> index
>
>__vmx_handle_exit() uses vcpu->run->internal.ndata as an index for
>an array access.  Since vcpu->run is (can be) mapped to a user address
>space with a writer permission, the 'ndata' could be updated by the
>user process at anytime (the user process can set it to outside the
>bounds of the array).
>So, it is not safe that __vmx_handle_exit() uses the 'ndata' that way.
>
>Fixes: 1aa561b1a4c0 ("kvm: x86: Add "last CPU" to some KVM_EXIT information")
>Signed-off-by: Reiji Watanabe <reijiw@google.com>
>Reviewed-by: Jim Mattson <jmattson@google.com>
>Message-Id: <20210413154739.490299-1-reijiw@google.com>
>Cc: stable@vger.kernel.org
>Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

I've resolved this by taking 8e5332402164 ("KVM: VMX: Convert
vcpu_vmx.exit_reason to a union").

-- 
Thanks,
Sasha