From patchwork Mon Dec 6 14:56:16 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 521473 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 3C01CC433FE for ; Mon, 6 Dec 2021 15:15:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1359266AbhLFPRF (ORCPT ); Mon, 6 Dec 2021 10:17:05 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54258 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1356080AbhLFPOk (ORCPT ); Mon, 6 Dec 2021 10:14:40 -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 97E54C08EB3E; Mon, 6 Dec 2021 07:06:55 -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 3D488B810F1; Mon, 6 Dec 2021 15:06:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8DD72C341C2; Mon, 6 Dec 2021 15:06:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1638803213; bh=SYADHwegBHLHX2IqBrWF5EqWP6v8l1dzTJnhdpZVJMc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Dm4cFnzd42s1sfGtAbu11R5/64hWZwQqWXg/5ntCPGx2sVzhV46LnZFTSbm1VWBNH VZN+UL2rvmSonEiCAvWYsjfw9i2HcH+drRkBo/eWc85Ufq5JgvXGiLVqouCbhJeABb Tyj55hpbilGqO2UBL7YZbfNOaWyNY++r+3mvVlf8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jan Beulich , Juergen Gross Subject: [PATCH 4.14 068/106] tty: hvc: replace BUG_ON() with negative return value Date: Mon, 6 Dec 2021 15:56:16 +0100 Message-Id: <20211206145557.824018686@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20211206145555.386095297@linuxfoundation.org> References: <20211206145555.386095297@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Juergen Gross commit e679004dec37566f658a255157d3aed9d762a2b7 upstream. Xen frontends shouldn't BUG() in case of illegal data received from their backends. So replace the BUG_ON()s when reading illegal data from the ring page with negative return values. Reviewed-by: Jan Beulich Signed-off-by: Juergen Gross Link: https://lore.kernel.org/r/20210707091045.460-1-jgross@suse.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/hvc/hvc_xen.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) --- a/drivers/tty/hvc/hvc_xen.c +++ b/drivers/tty/hvc/hvc_xen.c @@ -99,7 +99,11 @@ static int __write_console(struct xencon cons = intf->out_cons; prod = intf->out_prod; mb(); /* update queue values before going on */ - BUG_ON((prod - cons) > sizeof(intf->out)); + + if ((prod - cons) > sizeof(intf->out)) { + pr_err_once("xencons: Illegal ring page indices"); + return -EINVAL; + } while ((sent < len) && ((prod - cons) < sizeof(intf->out))) intf->out[MASK_XENCONS_IDX(prod++, intf->out)] = data[sent++]; @@ -127,7 +131,10 @@ static int domU_write_console(uint32_t v */ while (len) { int sent = __write_console(cons, data, len); - + + if (sent < 0) + return sent; + data += sent; len -= sent; @@ -151,7 +158,11 @@ static int domU_read_console(uint32_t vt cons = intf->in_cons; prod = intf->in_prod; mb(); /* get pointers before reading ring */ - BUG_ON((prod - cons) > sizeof(intf->in)); + + if ((prod - cons) > sizeof(intf->in)) { + pr_err_once("xencons: Illegal ring page indices"); + return -EINVAL; + } while (cons != prod && recv < len) buf[recv++] = intf->in[MASK_XENCONS_IDX(cons++, intf->in)];