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=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 537D6C3B1B5 for ; Fri, 14 Feb 2020 18:19:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 21CC0222C2 for ; Fri, 14 Feb 2020 18:19:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581704363; bh=Nqpuz4d+htBfl/ekXZG3MCc0UaBli9XkrokB59aAyT4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=eCOpM1TO8SSbJ0z4u2RiE32OIxDZSAcFdjTiy+gG5dC3Z49VUY/90UKsWMnDfapoH VDWnOGAk7UYfbGAiRLtBaBhJt1Pmc6v7UbirFL5Ehkzh2f/CyfqdSCt8sOkP6Sp/Sj UYakftwu7qGxBb2UTxEv8s9Fgk3suK5JHfXfOXuw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730499AbgBNPuc (ORCPT ); Fri, 14 Feb 2020 10:50:32 -0500 Received: from mail.kernel.org ([198.145.29.99]:54462 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730461AbgBNPuZ (ORCPT ); Fri, 14 Feb 2020 10:50:25 -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 82B2624686; Fri, 14 Feb 2020 15:50:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581695425; bh=Nqpuz4d+htBfl/ekXZG3MCc0UaBli9XkrokB59aAyT4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BwPnSkH4EX3pF5BiSxEFwtkr+JytUATZlbqrBNvrXogCCeM56SMQbHdQuPX++O8f9 2ore8igSWH/kKUS1sSXxyXciprA+atfMpfrANsAyGntGrfyu6XuoOaLdPVDpC/yfTk 0CbloSeqAWNGJazJKVKBT3pSW9Lrl4zv2mQei7xw= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jia-Ju Bai , Greg Kroah-Hartman , Sasha Levin Subject: [PATCH AUTOSEL 5.5 069/542] uio: fix a sleep-in-atomic-context bug in uio_dmem_genirq_irqcontrol() Date: Fri, 14 Feb 2020 10:41:01 -0500 Message-Id: <20200214154854.6746-69-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: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 81c88f7bbbcbb..f6ab3f28c8382 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; } -- 2.20.1