This is a note to let you know that I've just added the patch titled
KVM: x86: fix out-of-bounds accesses of rtc_eoi map
to the 4.8-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
kvm-x86-fix-out-of-bounds-accesses-of-rtc_eoi-map.patch
and it can be found in the queue-4.8 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 81cdb259fb6d8c1c4ecfeea389ff5a73c07f5755 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= <rkrcmar@xxxxxxxxxx>
Date: Wed, 23 Nov 2016 21:15:27 +0100
Subject: KVM: x86: fix out-of-bounds accesses of rtc_eoi map
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
From: Radim Krčmář <rkrcmar@xxxxxxxxxx>
commit 81cdb259fb6d8c1c4ecfeea389ff5a73c07f5755 upstream.
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@xxxxxxxxxx>
Fixes: af1bae5497b9 ("KVM: x86: bump KVM_MAX_VCPU_ID to 1023")
Reviewed-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
Signed-off-by: Radim Krčmář <rkrcmar@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/kvm/ioapic.c | 2 +-
arch/x86/kvm/ioapic.h | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)
--- a/arch/x86/kvm/ioapic.c
+++ b/arch/x86/kvm/ioapic.c
@@ -94,7 +94,7 @@ static unsigned long ioapic_read_indirec
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);
--- 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];
};
Patches currently in stable-queue which might be from rkrcmar@xxxxxxxxxx are
queue-4.8/kvm-x86-fix-out-of-bounds-access-in-lapic.patch
queue-4.8/kvm-x86-check-for-pic-and-ioapic-presence-before-use.patch
queue-4.8/kvm-x86-fix-out-of-bounds-accesses-of-rtc_eoi-map.patch
queue-4.8/kvm-x86-drop-error-recovery-in-em_jmp_far-and-em_ret_far.patch
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html