Messages in this thread | | | Subject | Re: [PATCH] KVM: x86: fix out-of-bounds accesses of rtc_eoi map | From | David Hildenbrand <> | Date | Thu, 24 Nov 2016 12:49:56 +0100 |
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Am 23.11.2016 um 21:15 schrieb Radim Krčmář: > KVM was using arrays of size KVM_MAX_VCPUS with vcpu_id, but ID can be > bigger that the maximal number of VCPUs, resulting in out-of-bounds > access. > > Found by syzkaller: > > BUG: KASAN: slab-out-of-bounds in __apic_accept_irq+0xb33/0xb50 at addr [...] > Write of size 1 by task a.out/27101 > CPU: 1 PID: 27101 Comm: a.out Not tainted 4.9.0-rc5+ #49 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 > [...] > Call Trace: > [...] __apic_accept_irq+0xb33/0xb50 arch/x86/kvm/lapic.c:905 > [...] kvm_apic_set_irq+0x10e/0x180 arch/x86/kvm/lapic.c:495 > [...] kvm_irq_delivery_to_apic+0x732/0xc10 arch/x86/kvm/irq_comm.c:86 > [...] ioapic_service+0x41d/0x760 arch/x86/kvm/ioapic.c:360 > [...] ioapic_set_irq+0x275/0x6c0 arch/x86/kvm/ioapic.c:222 > [...] kvm_ioapic_inject_all arch/x86/kvm/ioapic.c:235 > [...] kvm_set_ioapic+0x223/0x310 arch/x86/kvm/ioapic.c:670 > [...] kvm_vm_ioctl_set_irqchip arch/x86/kvm/x86.c:3668 > [...] kvm_arch_vm_ioctl+0x1a08/0x23c0 arch/x86/kvm/x86.c:3999 > [...] kvm_vm_ioctl+0x1fa/0x1a70 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3099 > > Reported-by: Dmitry Vyukov <dvyukov@google.com> > Cc: stable@vger.kernel.org > Fixes: af1bae5497b9 ("KVM: x86: bump KVM_MAX_VCPU_ID to 1023") > Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> > --- > Cc: Dmitry Vyukov <dvyukov@google.com> > Cc: Steve Rutherford <srutherford@google.com> > ---
Yes, the array and the bitmap are always accessed using vcpu_id, so this is correct.
Reviewed-by: David Hildenbrand <david@redhat.com>
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David
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