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authorPaolo Bonzini <pbonzini@redhat.com>2020-12-22 05:20:43 -0500
committerPaolo Bonzini <pbonzini@redhat.com>2021-01-07 18:07:32 -0500
commit2f80d502d627f30257ba7e3655e71c373b7d1a5a (patch)
tree6ae8dfc54febca3a30949453e538d4f9ec1915a7 /arch
parentb268b6f0bd36322358accb15c45683a9e1220231 (diff)
downloadlinux-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>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kvm/mmu.h2
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);