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 X-Spam-Level: X-Spam-Status: No, score=-8.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 99706C67863 for ; Mon, 22 Oct 2018 16:19:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E8E0C2064C for ; Mon, 22 Oct 2018 16:19:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E8E0C2064C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=zytor.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728598AbeJWAiV (ORCPT ); Mon, 22 Oct 2018 20:38:21 -0400 Received: from mga12.intel.com ([192.55.52.136]:3026 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727554AbeJWAiU (ORCPT ); Mon, 22 Oct 2018 20:38:20 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga006.jf.intel.com ([10.7.209.51]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 22 Oct 2018 09:19:11 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.54,412,1534834800"; d="scan'208";a="84637544" Received: from hanvin-mobl2.amr.corp.intel.com ([10.255.77.70]) by orsmga006.jf.intel.com with ESMTP; 22 Oct 2018 09:19:09 -0700 From: "H. Peter Anvin (Intel)" To: linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org Cc: "H. Peter Anvin" , Greg Kroah-Hartman , Jiri Slaby , Al Viro , Richard Henderson , Ivan Kokshaysky , Matt Turner , Thomas Gleixner , Kate Stewart , Philippe Ombredanne , Eugene Syromiatnikov , linux-alpha@vger.kernel.org, Alan Cox , stable@vger.kernel.org Subject: [PATCH stable v2 1/2] termios, tty/tty_baudrate.c: fix buffer overrun Date: Mon, 22 Oct 2018 09:19:04 -0700 Message-Id: <20181022161905.26589-1-hpa@zytor.com> X-Mailer: git-send-email 2.14.4 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "H. Peter Anvin" On architectures with CBAUDEX == 0 (Alpha and PowerPC), the code in tty_baudrate.c does not do any limit checking on the tty_baudrate[] array, and in fact a buffer overrun is possible on both architectures. Add a limit check to prevent that situation. This will be followed by a much bigger cleanup/simplification patch. Signed-off-by: H. Peter Anvin (Intel) Requested-by: Cc: Johan Hovold Cc: Greg Kroah-Hartman Cc: Jiri Slaby Cc: Al Viro Cc: Richard Henderson Cc: Ivan Kokshaysky Cc: Matt Turner Cc: Thomas Gleixner Cc: Kate Stewart Cc: Philippe Ombredanne Cc: Greg Kroah-Hartman Cc: Eugene Syromiatnikov Cc: Cc: Cc: Alan Cox Cc: --- drivers/tty/tty_baudrate.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/tty/tty_baudrate.c b/drivers/tty/tty_baudrate.c index 7576ceace571..f438eaa68246 100644 --- a/drivers/tty/tty_baudrate.c +++ b/drivers/tty/tty_baudrate.c @@ -77,7 +77,7 @@ speed_t tty_termios_baud_rate(struct ktermios *termios) else cbaud += 15; } - return baud_table[cbaud]; + return cbaud >= n_baud_table ? 0 : baud_table[cbaud]; } EXPORT_SYMBOL(tty_termios_baud_rate); @@ -113,7 +113,7 @@ speed_t tty_termios_input_baud_rate(struct ktermios *termios) else cbaud += 15; } - return baud_table[cbaud]; + return cbaud >= n_baud_table ? 0 : baud_table[cbaud]; #else /* IBSHIFT */ return tty_termios_baud_rate(termios); #endif /* IBSHIFT */ -- 2.14.4