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| author | Paolo Bonzini <pbonzini@redhat.com> | 2020-03-19 13:41:06 -0400 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-03-20 13:43:21 -0400 |
| commit | d33294541889b023068522270cd4153ddd8e4635 (patch) | |
| tree | 2d0fcb23c47dbfd49d49f4bae207590c56e6d6e3 /arch | |
| parent | 018cabb694e3923998fdc2908af5268f1d89f48f (diff) | |
| download | linux-d33294541889b023068522270cd4153ddd8e4635.tar.bz2 | |
KVM: x86: remove bogus user-triggerable WARN_ON
The WARN_ON is essentially comparing a user-provided value with 0. It is
trivial to trigger it just by passing garbage to KVM_SET_CLOCK. Guests
can break if you do so, but the same applies to every KVM_SET_* ioctl.
So, if it hurts when you do like this, just do not do it.
Reported-by: syzbot+00be5da1d75f1cc95f6b@syzkaller.appspotmail.com
Fixes: 9446e6fce0ab ("KVM: x86: fix WARN_ON check of an unsigned less than zero")
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kvm/x86.c | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 3156e25b0774..d65ff2008cf1 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2444,7 +2444,6 @@ static int kvm_guest_time_update(struct kvm_vcpu *v) vcpu->hv_clock.tsc_timestamp = tsc_timestamp; vcpu->hv_clock.system_time = kernel_ns + v->kvm->arch.kvmclock_offset; vcpu->last_guest_tsc = tsc_timestamp; - WARN_ON((s64)vcpu->hv_clock.system_time < 0); /* If the host uses TSC clocksource, then it is stable */ pvclock_flags = 0; |