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| author | Sean Christopherson <seanjc@google.com> | 2021-02-08 12:19:40 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-02-26 10:13:01 +0100 |
| commit | 3320aa64c322512ccc17406c0d60681177a8cac5 (patch) | |
| tree | 54be45a22a24e8a3eea26e2542fef06b4e4dce58 /virt | |
| parent | a42150f1c965d23ea858c1931f53b591d9e817d4 (diff) | |
| download | linux-stable-3320aa64c322512ccc17406c0d60681177a8cac5.tar.gz linux-stable-3320aa64c322512ccc17406c0d60681177a8cac5.tar.bz2 linux-stable-3320aa64c322512ccc17406c0d60681177a8cac5.zip | |
KVM: Use kvm_pfn_t for local PFN variable in hva_to_pfn_remapped()
commit a9545779ee9e9e103648f6f2552e73cfe808d0f4 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 bd2fae8da794 ("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: add6a0cd1c5b ("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>
Diffstat (limited to 'virt')
| -rw-r--r-- | virt/kvm/kvm_main.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 1bd7e5ee3550..ed4d2e3a0071 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1888,7 +1888,7 @@ static int hva_to_pfn_remapped(struct vm_area_struct *vma, bool write_fault, bool *writable, kvm_pfn_t *p_pfn) { - unsigned long pfn; + kvm_pfn_t pfn; pte_t *ptep; spinlock_t *ptl; int r; |