From 14d3ae8df568a08903269006b345de5bdf173f55 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Thu, 23 Oct 2014 14:54:14 +0200 Subject: [PATCH 1/1] KVM: emulate: avoid accessing NULL ctxt->memopp 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. Reported-by: Andy Lutomirski Cc: stable@vger.kernel.org Fixes: 41061cdb98a0bec464278b4db8e894a3121671f5 Signed-off-by: Paolo Bonzini --- 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