This is a note to let you know that I've just added the patch titled
kvm: x86: Check memopp before dereference (CVE-2016-8630)
to the 4.4-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-x86-check-memopp-before-dereference-cve-2016-8630.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From d9092f52d7e61dd1557f2db2400ddb430e85937e Mon Sep 17 00:00:00 2001
From: Owen Hofmann <osh@xxxxxxxxxx>
Date: Thu, 27 Oct 2016 11:25:52 -0700
Subject: kvm: x86: Check memopp before dereference (CVE-2016-8630)
From: Owen Hofmann <osh@xxxxxxxxxx>
commit d9092f52d7e61dd1557f2db2400ddb430e85937e upstream.
Commit 41061cdb98 ("KVM: emulate: do not initialize memopp") removes a
check for non-NULL under incorrect assumptions. An undefined instruction
with a ModR/M byte with Mod=0 and R/M-5 (e.g. 0xc7 0x15) will attempt
to dereference a null pointer here.
Fixes: 41061cdb98a0bec464278b4db8e894a3121671f5
Message-Id: <1477592752-126650-2-git-send-email-osh@xxxxxxxxxx>
Signed-off-by: Owen Hofmann <osh@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/kvm/emulate.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -5033,7 +5033,7 @@ done_prefixes:
/* Decode and fetch the destination operand: register or memory. */
rc = decode_operand(ctxt, &ctxt->dst, (ctxt->d >> DstShift) & OpMask);
- if (ctxt->rip_relative)
+ if (ctxt->rip_relative && likely(ctxt->memopp))
ctxt->memopp->addr.mem.ea = address_mask(ctxt,
ctxt->memopp->addr.mem.ea + ctxt->_eip);
Patches currently in stable-queue which might be from osh@xxxxxxxxxx are
queue-4.4/kvm-x86-check-memopp-before-dereference-cve-2016-8630.patch
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