This is a note to let you know that I've just added the patch titled
KVM: Fix bounds checking in ioapic indirect register reads (CVE-2013-1798)
to the 3.4-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-fix-bounds-checking-in-ioapic-indirect-register-reads-cve-2013-1798.patch
and it can be found in the queue-3.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From a2c118bfab8bc6b8bb213abfc35201e441693d55 Mon Sep 17 00:00:00 2001
From: Andy Honig <ahonig@xxxxxxxxxx>
Date: Wed, 20 Feb 2013 14:49:16 -0800
Subject: KVM: Fix bounds checking in ioapic indirect register reads (CVE-2013-1798)
From: Andy Honig <ahonig@xxxxxxxxxx>
commit a2c118bfab8bc6b8bb213abfc35201e441693d55 upstream.
If the guest specifies a IOAPIC_REG_SELECT with an invalid value and follows
that with a read of the IOAPIC_REG_WINDOW KVM does not properly validate
that request. ioapic_read_indirect contains an
ASSERT(redir_index < IOAPIC_NUM_PINS), but the ASSERT has no effect in
non-debug builds. In recent kernels this allows a guest to cause a kernel
oops by reading invalid memory. In older kernels (pre-3.3) this allows a
guest to read from large ranges of host memory.
Tested: tested against apic unit tests.
Signed-off-by: Andrew Honig <ahonig@xxxxxxxxxx>
Signed-off-by: Marcelo Tosatti <mtosatti@xxxxxxxxxx>
Cc: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
virt/kvm/ioapic.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
--- a/virt/kvm/ioapic.c
+++ b/virt/kvm/ioapic.c
@@ -73,9 +73,12 @@ static unsigned long ioapic_read_indirec
u32 redir_index = (ioapic->ioregsel - 0x10) >> 1;
u64 redir_content;
- ASSERT(redir_index < IOAPIC_NUM_PINS);
+ if (redir_index < IOAPIC_NUM_PINS)
+ redir_content =
+ ioapic->redirtbl[redir_index].bits;
+ else
+ redir_content = ~0ULL;
- redir_content = ioapic->redirtbl[redir_index].bits;
result = (ioapic->ioregsel & 0x1) ?
(redir_content >> 32) & 0xffffffff :
redir_content & 0xffffffff;
Patches currently in stable-queue which might be from ahonig@xxxxxxxxxx are
queue-3.4/kvm-allow-cross-page-reads-and-writes-from-cached-translations.patch
queue-3.4/kvm-fix-bounds-checking-in-ioapic-indirect-register-reads-cve-2013-1798.patch
queue-3.4/kvm-x86-convert-msr_kvm_system_time-to-use-gfn_to_hva_cache-functions-cve-2013-1797.patch
queue-3.4/kvm-x86-fix-for-buffer-overflow-in-handling-of-msr_kvm_system_time-cve-2013-1796.patch
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