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=-9.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 14F6CC433DF for ; Mon, 12 Oct 2020 13:35:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B876D21D7F for ; Mon, 12 Oct 2020 13:35:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602509740; bh=YMQU0ils7PKqdHzaH5Vzf6RDLvYLthgHpJR/gUwTzVc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=LMtJ3n6eKUwfceGMewmFZ45SHzh3NvxTJBl4biyQRypYjGCwzlzMr/IgDvMOZwzFg lJR6gUB43T27DVD5tdzLa7F70OUTaxAzEEE4o6STke1Tag9uF2w7mEOl8BxRvoxTnS 7b30D8qPCXTTGchWYPosJLbQjXkFNw2hQlfp1YeM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729292AbgJLNfj (ORCPT ); Mon, 12 Oct 2020 09:35:39 -0400 Received: from mail.kernel.org ([198.145.29.99]:36740 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726745AbgJLNe2 (ORCPT ); Mon, 12 Oct 2020 09:34:28 -0400 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 A7C4822246; Mon, 12 Oct 2020 13:34:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602509661; bh=YMQU0ils7PKqdHzaH5Vzf6RDLvYLthgHpJR/gUwTzVc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=glxUPwRZ9yiohulUDGgfdWLp/rOL5N1tAvJq1o5Y5PfUmGjqVFVLFbl4kYuz5WK5t qxtwRFEpZThmARWdoh+9fyiWvsaP9DTl2wVEvm3n9OUJNWM8gjU9NYaJjUjSydXkO8 RJjNQTz3b2gUf0WyBQvyOQpwtqqkFOio89J2Feqw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot , Geert Uytterhoeven , Tetsuo Handa , stable , "Nobuhiro Iwamatsu (CIP)" Subject: [PATCH 4.9 31/54] driver core: Fix probe_count imbalance in really_probe() Date: Mon, 12 Oct 2020 15:26:53 +0200 Message-Id: <20201012132631.025929974@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201012132629.585664421@linuxfoundation.org> References: <20201012132629.585664421@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Tetsuo Handa commit b292b50b0efcc7095d8bf15505fba6909bb35dce upstream. syzbot is reporting hung task in wait_for_device_probe() [1]. At least, we always need to decrement probe_count if we incremented probe_count in really_probe(). However, since I can't find "Resources present before probing" message in the console log, both "this message simply flowed off" and "syzbot is not hitting this path" will be possible. Therefore, while we are at it, let's also prepare for concurrent wait_for_device_probe() calls by replacing wake_up() with wake_up_all(). [1] https://syzkaller.appspot.com/bug?id=25c833f1983c9c1d512f4ff860dd0d7f5a2e2c0f Reported-by: syzbot Fixes: 7c35e699c88bd607 ("driver core: Print device when resources present in really_probe()") Cc: Geert Uytterhoeven Signed-off-by: Tetsuo Handa Cc: stable Link: https://lore.kernel.org/r/20200713021254.3444-1-penguin-kernel@I-love.SAKURA.ne.jp [iwamatsu: Drop patch for deferred_probe_timeout_work_func()] Signed-off-by: Nobuhiro Iwamatsu (CIP) Signed-off-by: Greg Kroah-Hartman --- drivers/base/dd.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -343,7 +343,8 @@ static int really_probe(struct device *d drv->bus->name, __func__, drv->name, dev_name(dev)); if (!list_empty(&dev->devres_head)) { dev_crit(dev, "Resources present before probing\n"); - return -EBUSY; + ret = -EBUSY; + goto done; } re_probe: @@ -446,7 +447,7 @@ pinctrl_bind_failed: ret = 0; done: atomic_dec(&probe_count); - wake_up(&probe_waitqueue); + wake_up_all(&probe_waitqueue); return ret; }