From patchwork Fri Feb 21 07:37:34 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 230718 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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 D7D25C35640 for ; Fri, 21 Feb 2020 08:38:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A4ECE206ED for ; Fri, 21 Feb 2020 08:38:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582274292; bh=lF92hF88zHd33XQxLnxONLpWHtNulppo4iZqNdajo2M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=a9eCuqzVPYFp1ylcOCs24Zw6vktcfqti8fUDQUhdXAK9kLLgFPHSyBErQIn2u8QOF /tVr/eJNyrLI82X+BHW3cQc2qsqrh6nIObd9tN9v+iMjB8ktYuUktAen5i6rUyaQXu 7qd5p3dw89sR9i0ERSHv6ofNmftiIqoLJLboCae4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731130AbgBUID2 (ORCPT ); Fri, 21 Feb 2020 03:03:28 -0500 Received: from mail.kernel.org ([198.145.29.99]:36238 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731001AbgBUID1 (ORCPT ); Fri, 21 Feb 2020 03:03:27 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 31B0A2465D; Fri, 21 Feb 2020 08:03:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582272206; bh=lF92hF88zHd33XQxLnxONLpWHtNulppo4iZqNdajo2M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=otaDJvE2VSmfFgu7Jc60jYvs5hvIYOp7gR8LDCnG9iNcs3jYsVWWhIhHYNKnav4pR MzqktORIv7jUbJ1E5hCz/NGxWBwzveCM05FpjvdnuoB3jor70H9rdjbXoGuD8NPTh6 QvnW4IVnhhhernNLGw1gARXKK5w2SqfABYZUJ8A4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jia-Ju Bai , Sasha Levin Subject: [PATCH 5.4 055/344] uio: fix a sleep-in-atomic-context bug in uio_dmem_genirq_irqcontrol() Date: Fri, 21 Feb 2020 08:37:34 +0100 Message-Id: <20200221072354.062239864@linuxfoundation.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200221072349.335551332@linuxfoundation.org> References: <20200221072349.335551332@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Jia-Ju Bai [ Upstream commit b74351287d4bd90636c3f48bc188c2f53824c2d4 ] The driver may sleep while holding a spinlock. The function call path (from bottom to top) in Linux 4.19 is: kernel/irq/manage.c, 523: synchronize_irq in disable_irq drivers/uio/uio_dmem_genirq.c, 140: disable_irq in uio_dmem_genirq_irqcontrol drivers/uio/uio_dmem_genirq.c, 134: _raw_spin_lock_irqsave in uio_dmem_genirq_irqcontrol synchronize_irq() can sleep at runtime. To fix this bug, disable_irq() is called without holding the spinlock. This bug is found by a static analysis tool STCheck written by myself. Signed-off-by: Jia-Ju Bai Link: https://lore.kernel.org/r/20191218094405.6009-1-baijiaju1990@gmail.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/uio/uio_dmem_genirq.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/uio/uio_dmem_genirq.c b/drivers/uio/uio_dmem_genirq.c index ebcf1434e296d..44858f70f5f52 100644 --- a/drivers/uio/uio_dmem_genirq.c +++ b/drivers/uio/uio_dmem_genirq.c @@ -132,11 +132,13 @@ static int uio_dmem_genirq_irqcontrol(struct uio_info *dev_info, s32 irq_on) if (irq_on) { if (test_and_clear_bit(0, &priv->flags)) enable_irq(dev_info->irq); + spin_unlock_irqrestore(&priv->lock, flags); } else { - if (!test_and_set_bit(0, &priv->flags)) + if (!test_and_set_bit(0, &priv->flags)) { + spin_unlock_irqrestore(&priv->lock, flags); disable_irq(dev_info->irq); + } } - spin_unlock_irqrestore(&priv->lock, flags); return 0; }