From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A0673C433FE for ; Tue, 8 Nov 2022 13:42:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234436AbiKHNmJ (ORCPT ); Tue, 8 Nov 2022 08:42:09 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39904 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233858AbiKHNmC (ORCPT ); Tue, 8 Nov 2022 08:42:02 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DEC9817590 for ; Tue, 8 Nov 2022 05:42:01 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 8E6DCB81AEE for ; Tue, 8 Nov 2022 13:42:00 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DD98CC433C1; Tue, 8 Nov 2022 13:41:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1667914919; bh=wJNxnrsaIA+ITW16+/BWvHChjaMd30W5huGjAiFwY2I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sZ5oupAzv6r7ljU0zsnYlMgBXJ9ZEbjnSox49qQKksziZlJRkZDC+1Kb6BUIilSNC EC3uqP2t2V66CLJ1LUKSjI46qGzMxjOMxyafBsx+sN1+y+hY1V0KYvHXLxY6cgQbKI +AHtx0IOfo5IeTUJTwrdAtwjGAFPYu/D6P7W9PSU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Maxim Levitsky , Paolo Bonzini Subject: [PATCH 4.9 27/30] KVM: x86: emulator: em_sysexit should update ctxt->mode Date: Tue, 8 Nov 2022 14:39:15 +0100 Message-Id: <20221108133327.749655871@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221108133326.715586431@linuxfoundation.org> References: <20221108133326.715586431@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Maxim Levitsky commit 5015bb89b58225f97df6ac44383e7e8c8662c8c9 upstream. SYSEXIT is one of the instructions that can change the processor mode, thus ctxt->mode should be updated after it. Note that this is likely a benign bug, because the only problematic mode change is from 32 bit to 64 bit which can lead to truncation of RIP, and it is not possible to do with sysexit, since sysexit running in 32 bit mode will be limited to 32 bit version. Signed-off-by: Maxim Levitsky Message-Id: <20221025124741.228045-11-mlevitsk@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/emulate.c | 1 + 1 file changed, 1 insertion(+) --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -2881,6 +2881,7 @@ static int em_sysexit(struct x86_emulate ops->set_segment(ctxt, ss_sel, &ss, 0, VCPU_SREG_SS); ctxt->_eip = rdx; + ctxt->mode = usermode; *reg_write(ctxt, VCPU_REGS_RSP) = rcx; return X86EMUL_CONTINUE;