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| author | Radim Krčmář <rkrcmar@redhat.com> | 2016-11-23 21:15:27 +0100 |
|---|---|---|
| committer | Radim Krčmář <rkrcmar@redhat.com> | 2016-11-24 18:37:19 +0100 |
| commit | 81cdb259fb6d8c1c4ecfeea389ff5a73c07f5755 (patch) | |
| tree | c0e087707bb37d045abc32dce1888afcfa4c977d /arch | |
| parent | 2117d5398c81554fbf803f5fd1dc55eb78216c0c (diff) | |
| download | lwn-81cdb259fb6d8c1c4ecfeea389ff5a73c07f5755.tar.gz lwn-81cdb259fb6d8c1c4ecfeea389ff5a73c07f5755.zip | |
KVM: x86: fix out-of-bounds accesses of rtc_eoi map
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")
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kvm/ioapic.c | 2 | ||||
| -rw-r--r-- | arch/x86/kvm/ioapic.h | 4 |
2 files changed, 3 insertions, 3 deletions
diff --git a/arch/x86/kvm/ioapic.c b/arch/x86/kvm/ioapic.c index 1a22de70f7f7..6e219e5c07d2 100644 --- a/arch/x86/kvm/ioapic.c +++ b/arch/x86/kvm/ioapic.c @@ -94,7 +94,7 @@ static unsigned long ioapic_read_indirect(struct kvm_ioapic *ioapic, static void rtc_irq_eoi_tracking_reset(struct kvm_ioapic *ioapic) { ioapic->rtc_status.pending_eoi = 0; - bitmap_zero(ioapic->rtc_status.dest_map.map, KVM_MAX_VCPUS); + bitmap_zero(ioapic->rtc_status.dest_map.map, KVM_MAX_VCPU_ID); } static void kvm_rtc_eoi_tracking_restore_all(struct kvm_ioapic *ioapic); diff --git a/arch/x86/kvm/ioapic.h b/arch/x86/kvm/ioapic.h index 7d2692a49657..1cc6e54436db 100644 --- a/arch/x86/kvm/ioapic.h +++ b/arch/x86/kvm/ioapic.h @@ -42,13 +42,13 @@ struct kvm_vcpu; struct dest_map { /* vcpu bitmap where IRQ has been sent */ - DECLARE_BITMAP(map, KVM_MAX_VCPUS); + DECLARE_BITMAP(map, KVM_MAX_VCPU_ID); /* * Vector sent to a given vcpu, only valid when * the vcpu's bit in map is set */ - u8 vectors[KVM_MAX_VCPUS]; + u8 vectors[KVM_MAX_VCPU_ID]; }; |