diff options
| author | Paolo Bonzini <pbonzini@redhat.com> | 2020-12-22 05:20:43 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-01-12 20:10:24 +0100 |
| commit | 1412cdde820467d212515798366c9cc242dc1c59 (patch) | |
| tree | 2253e5866df7aeb33fd4b715e2a30577e9c83b92 | |
| parent | 4dd18f7893df7d7d2eb50b27bea96e6076a51d67 (diff) | |
KVM: x86: fix shift out of bounds reported by UBSAN
commit 2f80d502d627f30257ba7e3655e71c373b7d1a5a upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -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 0b62c817f63f..05a02b8ace6b 100644 --- a/arch/x86/kvm/mmu.h +++ b/arch/x86/kvm/mmu.h @@ -53,7 +53,7 @@ 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_mask, u64 mmio_value); |