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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 EE298C2BA83 for ; Fri, 14 Feb 2020 18:20:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C255F20873 for ; Fri, 14 Feb 2020 18:20:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581704436; bh=UIOE5O03yqKGfd8b8kfCJ4j1pgm5NLZDnME+d1bMZ9E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Dnib3AwRfn9f1SzCHFGfaCRvMM0BjZjBVVoAPmJEtGVKgEcl9h42TvhmF9g9fVC2B 05G83Yp3ufMp8aOxTJoAGB58WrPaUDfVL8JT4tSG1OVQFhCHYTCmPf9MWoYl1bYcZf GvOcuQmip+vFhLj9ssKCPZhk+UEDiv/AbEj7udQI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730320AbgBNPuB (ORCPT ); Fri, 14 Feb 2020 10:50:01 -0500 Received: from mail.kernel.org ([198.145.29.99]:53588 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730306AbgBNPuA (ORCPT ); Fri, 14 Feb 2020 10:50:00 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E4A6724685; Fri, 14 Feb 2020 15:49:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581695399; bh=UIOE5O03yqKGfd8b8kfCJ4j1pgm5NLZDnME+d1bMZ9E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=N1yHIT90/teCMNmBtSemYhEVgSzc9AL7V1GpO8+NGt/hR0A+rneJ075RUP7cpuJkU arRgQO/M3JFO0JVZm6nBqPSQMxfAAnENf+r6F1MvhMbXxCcq2YX5O39BlhgjJxUjEJ 7p3pHYLBQwWwsBir6/2hmGTSFI6mLSe9nTkwgx3I= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jia-Ju Bai , Linus Walleij , Sasha Levin , linux-gpio@vger.kernel.org Subject: [PATCH AUTOSEL 5.5 050/542] gpio: gpio-grgpio: fix possible sleep-in-atomic-context bugs in grgpio_irq_map/unmap() Date: Fri, 14 Feb 2020 10:40:42 -0500 Message-Id: <20200214154854.6746-50-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200214154854.6746-1-sashal@kernel.org> References: <20200214154854.6746-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Jia-Ju Bai [ Upstream commit e36eaf94be8f7bc4e686246eed3cf92d845e2ef8 ] The driver may sleep while holding a spinlock. The function call path (from bottom to top) in Linux 4.19 is: drivers/gpio/gpio-grgpio.c, 261: request_irq in grgpio_irq_map drivers/gpio/gpio-grgpio.c, 255: _raw_spin_lock_irqsave in grgpio_irq_map drivers/gpio/gpio-grgpio.c, 318: free_irq in grgpio_irq_unmap drivers/gpio/gpio-grgpio.c, 299: _raw_spin_lock_irqsave in grgpio_irq_unmap request_irq() and free_irq() can sleep at runtime. To fix these bugs, request_irq() and free_irq() are called without holding the spinlock. These bugs are found by a static analysis tool STCheck written by myself. Signed-off-by: Jia-Ju Bai Link: https://lore.kernel.org/r/20191218132605.10594-1-baijiaju1990@gmail.com Signed-off-by: Linus Walleij Signed-off-by: Sasha Levin --- drivers/gpio/gpio-grgpio.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/gpio/gpio-grgpio.c b/drivers/gpio/gpio-grgpio.c index 08234e64993a9..3224933f4c8f4 100644 --- a/drivers/gpio/gpio-grgpio.c +++ b/drivers/gpio/gpio-grgpio.c @@ -253,17 +253,16 @@ static int grgpio_irq_map(struct irq_domain *d, unsigned int irq, lirq->irq = irq; uirq = &priv->uirqs[lirq->index]; if (uirq->refcnt == 0) { + spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags); ret = request_irq(uirq->uirq, grgpio_irq_handler, 0, dev_name(priv->dev), priv); if (ret) { dev_err(priv->dev, "Could not request underlying irq %d\n", uirq->uirq); - - spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags); - return ret; } + spin_lock_irqsave(&priv->gc.bgpio_lock, flags); } uirq->refcnt++; @@ -309,8 +308,11 @@ static void grgpio_irq_unmap(struct irq_domain *d, unsigned int irq) if (index >= 0) { uirq = &priv->uirqs[lirq->index]; uirq->refcnt--; - if (uirq->refcnt == 0) + if (uirq->refcnt == 0) { + spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags); free_irq(uirq->uirq, priv); + return; + } } spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags); -- 2.20.1