On Sun, Feb 09, 2020 at 01:34:11PM +0100, gregkh@linuxfoundation.org wrote:
The patch below does not apply to the 5.4-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 56871d444bc4d7ea66708775e62e2e0926384dbc Mon Sep 17 00:00:00 2001 From: Paolo Bonzini pbonzini@redhat.com Date: Sat, 18 Jan 2020 20:09:03 +0100 Subject: [PATCH] KVM: x86: fix overlap between SPTE_MMIO_MASK and generation
The SPTE_MMIO_MASK overlaps with the bits used to track MMIO generation number. A high enough generation number would overwrite the SPTE_SPECIAL_MASK region and cause the MMIO SPTE to be misinterpreted.
Likewise, setting bits 52 and 53 would also cause an incorrect generation number to be read from the PTE, though this was partially mitigated by the (useless if it weren't for the bug) removal of SPTE_SPECIAL_MASK from the spte in get_mmio_spte_generation. Drop that removal, and replace it with a compile-time assertion.
Fixes: 6eeb4ef049e7 ("KVM: x86: assign two bits to track SPTE kinds") Reported-by: Ben Gardon bgardon@google.com Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini pbonzini@redhat.com
Conflict due to file rename. I've fixed it up and queued up.