From patchwork Mon Nov 23 12:22:12 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 332264 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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, 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 0C8FAC64E7A for ; Mon, 23 Nov 2020 12:38:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B3C4720732 for ; Mon, 23 Nov 2020 12:38:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="xw2th9Xf" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732043AbgKWMiU (ORCPT ); Mon, 23 Nov 2020 07:38:20 -0500 Received: from mail.kernel.org ([198.145.29.99]:50844 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732077AbgKWMiS (ORCPT ); Mon, 23 Nov 2020 07:38:18 -0500 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3D04520732; Mon, 23 Nov 2020 12:38:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1606135097; bh=WnoWaPOliwfCDnB34vVQAmgvOEREp88/2DhlefrORCw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xw2th9Xf2TZUFmQHaZq1Gji1sRe7VMxDq7c8/xfnKcdRIUJTO/IJlaBrVa1RH5fAk jVBaTlA+kfDGsJQZmbJLK4evPYs2MAtzkaR94R2KDo9yy3z2nThVj98E2WksHIfNEP DHqCJ1SufwD47rpbifw4Zr5sM6sd8hePcJMmIVnc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Naresh Kamboju , Arnd Bergmann , Nishanth Menon , Mark Brown , Sasha Levin Subject: [PATCH 5.4 104/158] regulator: ti-abb: Fix array out of bound read access on the first transition Date: Mon, 23 Nov 2020 13:22:12 +0100 Message-Id: <20201123121824.954536672@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201123121819.943135899@linuxfoundation.org> References: <20201123121819.943135899@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Nishanth Menon [ Upstream commit 2ba546ebe0ce2af47833d8912ced9b4a579f13cb ] At the start of driver initialization, we do not know what bias setting the bootloader has configured the system for and we only know for certain the very first time we do a transition. However, since the initial value of the comparison index is -EINVAL, this negative value results in an array out of bound access on the very first transition. Since we don't know what the setting is, we just set the bias configuration as there is nothing to compare against. This prevents the array out of bound access. NOTE: Even though we could use a more relaxed check of "< 0" the only valid values(ignoring cosmic ray induced bitflips) are -EINVAL, 0+. Fixes: 40b1936efebd ("regulator: Introduce TI Adaptive Body Bias(ABB) on-chip LDO driver") Link: https://lore.kernel.org/linux-mm/CA+G9fYuk4imvhyCN7D7T6PMDH6oNp6HDCRiTUKMQ6QXXjBa4ag@mail.gmail.com/ Reported-by: Naresh Kamboju Reviewed-by: Arnd Bergmann Signed-off-by: Nishanth Menon Link: https://lore.kernel.org/r/20201118145009.10492-1-nm@ti.com Signed-off-by: Mark Brown Signed-off-by: Sasha Levin --- drivers/regulator/ti-abb-regulator.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/regulator/ti-abb-regulator.c b/drivers/regulator/ti-abb-regulator.c index 89b9314d64c9d..016330f909c09 100644 --- a/drivers/regulator/ti-abb-regulator.c +++ b/drivers/regulator/ti-abb-regulator.c @@ -342,8 +342,17 @@ static int ti_abb_set_voltage_sel(struct regulator_dev *rdev, unsigned sel) return ret; } - /* If data is exactly the same, then just update index, no change */ info = &abb->info[sel]; + /* + * When Linux kernel is starting up, we are'nt sure of the + * Bias configuration that bootloader has configured. + * So, we get to know the actual setting the first time + * we are asked to transition. + */ + if (abb->current_info_idx == -EINVAL) + goto just_set_abb; + + /* If data is exactly the same, then just update index, no change */ oinfo = &abb->info[abb->current_info_idx]; if (!memcmp(info, oinfo, sizeof(*info))) { dev_dbg(dev, "%s: Same data new idx=%d, old idx=%d\n", __func__, @@ -351,6 +360,7 @@ static int ti_abb_set_voltage_sel(struct regulator_dev *rdev, unsigned sel) goto out; } +just_set_abb: ret = ti_abb_set_opp(rdev, abb, info); out: