Messages in this thread Patch in this message | | | From | Paolo Bonzini <> | Subject | [PATCH 10/14] KVM: emulate: avoid accessing NULL ctxt->memopp | Date | Fri, 24 Oct 2014 17:07:21 +0200 |
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A failure to decode the instruction can cause a NULL pointer access. This is fixed simply by moving the "done" label as close as possible to the return.
This fixes CVE-2014-8481.
Reported-by: Andy Lutomirski <luto@amacapital.net> Cc: stable@vger.kernel.org Fixes: 41061cdb98a0bec464278b4db8e894a3121671f5 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> --- arch/x86/kvm/emulate.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 02c8ea804aaf..eb3b1c46f995 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -4580,10 +4580,10 @@ done_prefixes: /* Decode and fetch the destination operand: register or memory. */ rc = decode_operand(ctxt, &ctxt->dst, (ctxt->d >> DstShift) & OpMask); -done: if (ctxt->rip_relative) ctxt->memopp->addr.mem.ea += ctxt->_eip; +done: return (rc != X86EMUL_CONTINUE) ? EMULATION_FAILED : EMULATION_OK; } -- 1.8.3.1
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