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=-17.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 23CE0C4338F for ; Sun, 25 Jul 2021 18:08:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 02A4D60F35 for ; Sun, 25 Jul 2021 18:08:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230303AbhGYR2X (ORCPT ); Sun, 25 Jul 2021 13:28:23 -0400 Received: from mail.kernel.org ([198.145.29.99]:50938 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229545AbhGYR2W (ORCPT ); Sun, 25 Jul 2021 13:28:22 -0400 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (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 E60FD60E78; Sun, 25 Jul 2021 18:08:52 +0000 (UTC) Received: from sofa.misterjones.org ([185.219.108.64] helo=wait-a-minute.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1m7iYV-000t8G-8w; Sun, 25 Jul 2021 19:08:51 +0100 From: Marc Zyngier To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: kernel-team@android.com, stable@vger.kernel.org, Amelie Delaunay , Linus Walleij , Maxime Coquelin , Alexandre Torgue Subject: [PATCH] pinctrl: stmfx: Fix hazardous u8[] to unsigned long cast Date: Sun, 25 Jul 2021 19:08:30 +0100 Message-Id: <20210725180830.250218-1-maz@kernel.org> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kernel-team@android.com, stable@vger.kernel.org, amelie.delaunay@foss.st.com, linus.walleij@linaro.org, mcoquelin.stm32@gmail.com, alexandre.torgue@foss.st.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org Casting a small array of u8 to an unsigned long is *never* OK: - it does funny thing when the array size is less than that of a long, as it accesses random places in the stack - it makes everything even more fun with a BE kernel Fix this by building the unsigned long used as a bitmap byte by byte, in a way that works across endianess and has no undefined behaviours. An extra BUILD_BUG_ON() catches the unlikely case where the array would be larger than a single unsigned long. Fixes: 1490d9f841b1 ("pinctrl: Add STMFX GPIO expander Pinctrl/GPIO driver") Signed-off-by: Marc Zyngier Cc: stable@vger.kernel.org Cc: Amelie Delaunay Cc: Linus Walleij Cc: Maxime Coquelin Cc: Alexandre Torgue --- drivers/pinctrl/pinctrl-stmfx.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/pinctrl/pinctrl-stmfx.c b/drivers/pinctrl/pinctrl-stmfx.c index 008c83107a3c..5fa2488fae87 100644 --- a/drivers/pinctrl/pinctrl-stmfx.c +++ b/drivers/pinctrl/pinctrl-stmfx.c @@ -566,7 +566,7 @@ static irqreturn_t stmfx_pinctrl_irq_thread_fn(int irq, void *dev_id) u8 pending[NR_GPIO_REGS]; u8 src[NR_GPIO_REGS] = {0, 0, 0}; unsigned long n, status; - int ret; + int i, ret; ret = regmap_bulk_read(pctl->stmfx->map, STMFX_REG_IRQ_GPI_PENDING, &pending, NR_GPIO_REGS); @@ -576,7 +576,9 @@ static irqreturn_t stmfx_pinctrl_irq_thread_fn(int irq, void *dev_id) regmap_bulk_write(pctl->stmfx->map, STMFX_REG_IRQ_GPI_SRC, src, NR_GPIO_REGS); - status = *(unsigned long *)pending; + BUILD_BUG_ON(NR_GPIO_REGS > sizeof(status)); + for (i = 0, status = 0; i < NR_GPIO_REGS; i++) + status |= (unsigned long)pending[i] << (i * 8); for_each_set_bit(n, &status, gc->ngpio) { handle_nested_irq(irq_find_mapping(gc->irq.domain, n)); stmfx_pinctrl_irq_toggle_trigger(pctl, n); -- 2.30.2