From patchwork Wed Feb 8 15:51:44 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luca Coelho X-Patchwork-Id: 9562715 X-Patchwork-Delegate: luca@coelho.fi Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 0BD0B60434 for ; Wed, 8 Feb 2017 15:53:17 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 06E76283EE for ; Wed, 8 Feb 2017 15:53:17 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id EFCB528506; Wed, 8 Feb 2017 15:53:16 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RCVD_IN_SBL autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A0CF6283EE for ; Wed, 8 Feb 2017 15:53:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932065AbdBHPxQ (ORCPT ); Wed, 8 Feb 2017 10:53:16 -0500 Received: from paleale.coelho.fi ([176.9.41.70]:39334 "EHLO farmhouse.coelho.fi" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754754AbdBHPxM (ORCPT ); Wed, 8 Feb 2017 10:53:12 -0500 Received: from [192.40.95.5] (helo=localhost.localdomain) by farmhouse.coelho.fi with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.88) (envelope-from ) id 1cbUXK-0002Q5-0C; Wed, 08 Feb 2017 17:52:02 +0200 From: Luca Coelho To: linux-wireless@vger.kernel.org Cc: kvalo@codeaurora.org, Emmanuel Grumbach , Luca Coelho Date: Wed, 8 Feb 2017 17:51:44 +0200 Message-Id: <20170208155149.1704-4-luca@coelho.fi> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170208155149.1704-1-luca@coelho.fi> References: <20170208112322.29413-1-luca@coelho.fi> <20170208155149.1704-1-luca@coelho.fi> X-SA-Exim-Connect-IP: 192.40.95.5 X-SA-Exim-Mail-From: luca@coelho.fi Subject: [PATCH 12/17] iwlwifi: mvm: don't call << operator with a negative value X-SA-Exim-Version: 4.2.1 (built Tue, 02 Aug 2016 21:08:31 +0000) X-SA-Exim-Scanned: Yes (on farmhouse.coelho.fi) Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Emmanuel Grumbach In https://bugzilla.kernel.org/show_bug.cgi?id=177341 Bob reported a UBSAN WARNING on rs.c in iwldvm. Fix the same bug in iwlmvm. This because i = index - 1; for (mask = (1 << i); i >= 0; i--, mask >>= 1) is unsafe: i could be negative and hence we can call << on a negative value. This bug doesn't have any real impact since the condition of the for loop will prevent any usage of mask. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=177341 Signed-off-by: Emmanuel Grumbach Signed-off-by: Luca Coelho --- drivers/net/wireless/intel/iwlwifi/mvm/rs.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/rs.c b/drivers/net/wireless/intel/iwlwifi/mvm/rs.c index 13be9a5b83ee..ce907c58ebf6 100644 --- a/drivers/net/wireless/intel/iwlwifi/mvm/rs.c +++ b/drivers/net/wireless/intel/iwlwifi/mvm/rs.c @@ -972,7 +972,9 @@ static u16 rs_get_adjacent_rate(struct iwl_mvm *mvm, u8 index, u16 rate_mask, /* Find the previous rate that is in the rate mask */ i = index - 1; - for (mask = (1 << i); i >= 0; i--, mask >>= 1) { + if (i >= 0) + mask = BIT(i); + for (; i >= 0; i--, mask >>= 1) { if (rate_mask & mask) { low = i; break;