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| author | Paolo Bonzini <pbonzini@redhat.com> | 2020-12-22 05:20:43 -0500 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2021-01-07 18:07:32 -0500 |
| commit | 2f80d502d627f30257ba7e3655e71c373b7d1a5a (patch) | |
| tree | 6ae8dfc54febca3a30949453e538d4f9ec1915a7 | |
| parent | b268b6f0bd36322358accb15c45683a9e1220231 (diff) | |
| download | linux-2f80d502d627f30257ba7e3655e71c373b7d1a5a.tar.bz2 | |
KVM: x86: fix shift out of bounds reported by UBSAN
Since we know that e >= s, we can reassociate the left shift,
changing the shifted number from 1 to 2 in exchange for
decreasing the right hand side by 1.
Reported-by: syzbot+e87846c48bf72bc85311@syzkaller.appspotmail.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | arch/x86/kvm/mmu.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h index 9c4a9c8e43d9..581925e476d6 100644 --- a/arch/x86/kvm/mmu.h +++ b/arch/x86/kvm/mmu.h @@ -49,7 +49,7 @@ static inline u64 rsvd_bits(int s, int e) if (e < s) return 0; - return ((1ULL << (e - s + 1)) - 1) << s; + return ((2ULL << (e - s)) - 1) << s; } void kvm_mmu_set_mmio_spte_mask(u64 mmio_value, u64 access_mask); |