linux-stable/virt/kvm
Sean Christopherson 3320aa64c3 KVM: Use kvm_pfn_t for local PFN variable in hva_to_pfn_remapped()
commit a9545779ee upstream.

Use kvm_pfn_t, a.k.a. u64, for the local 'pfn' variable when retrieving
a so called "remapped" hva/pfn pair.  In theory, the hva could resolve to
a pfn in high memory on a 32-bit kernel.

This bug was inadvertantly exposed by commit bd2fae8da7 ("KVM: do not
assume PTE is writable after follow_pfn"), which added an error PFN value
to the mix, causing gcc to comlain about overflowing the unsigned long.

  arch/x86/kvm/../../../virt/kvm/kvm_main.c: In function ‘hva_to_pfn_remapped’:
  include/linux/kvm_host.h:89:30: error: conversion from ‘long long unsigned int’
                                  to ‘long unsigned int’ changes value from
                                  ‘9218868437227405314’ to ‘2’ [-Werror=overflow]
   89 | #define KVM_PFN_ERR_RO_FAULT (KVM_PFN_ERR_MASK + 2)
      |                              ^
virt/kvm/kvm_main.c:1935:9: note: in expansion of macro ‘KVM_PFN_ERR_RO_FAULT’

Cc: stable@vger.kernel.org
Fixes: add6a0cd1c ("KVM: MMU: try to fix up page faults before giving up")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210208201940.1258328-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-26 10:13:01 +01:00
..
async_pf.c mm/gup: remove task_struct pointer for all gup code 2020-08-12 10:58:04 -07:00
async_pf.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 504 2019-06-19 17:09:56 +02:00
coalesced_mmio.c KVM: Fix spelling in code comments 2020-05-16 15:05:01 +01:00
coalesced_mmio.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
eventfd.c kvm/eventfd: move wildcard calculation outside loop 2020-09-28 07:57:08 -04:00
irqchip.c KVM/arm updates for 5.3 2019-07-11 15:14:16 +02:00
Kconfig entry: Provide infrastructure for work before transitioning to guest mode 2020-07-24 15:03:42 +02:00
kvm_main.c KVM: Use kvm_pfn_t for local PFN variable in hva_to_pfn_remapped() 2021-02-26 10:13:01 +01:00
vfio.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
vfio.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00