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=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 389BFC43467 for ; Mon, 12 Oct 2020 13:40:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D06CF221FC for ; Mon, 12 Oct 2020 13:40:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602510003; bh=qUM7Ytv60gu663GexdikDZ2Nncf93/ZXvsiw9W78LH0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=pSG65+EL6sSr4Q1BWQPYLRkHgj94tIzi6F7O7Ma/QJwTV95UkrWMpj9NYqPgbl6Y+ Y6YaASNeekXnpk/YnwhF9GTDAU/4T2Wr1e8KJj+JnCk7myxuPbd/TtTtiX++3ts7xU dq0XXKcxdCjzFsFI5Da1nO+Kfzd2r/8nCdAHKxHY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731369AbgJLNjZ (ORCPT ); Mon, 12 Oct 2020 09:39:25 -0400 Received: from mail.kernel.org ([198.145.29.99]:40142 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731244AbgJLNio (ORCPT ); Mon, 12 Oct 2020 09:38:44 -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 C9C9E22258; Mon, 12 Oct 2020 13:38:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602509912; bh=qUM7Ytv60gu663GexdikDZ2Nncf93/ZXvsiw9W78LH0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GVxPkpRQsFjOfcFBtUR2FrCdux3wamef+YrsT2RJxae6K2UAsAQhQ3SpwOmnwwYFz 4nXLM3htaapRxFBx8BmAH3y3penWL2O3nyPJ8Kumtg7mCfl2pMFrRT/RFCJVRM7r5c Ryo4LCx5HFY2GsbbhMx+7RMlE8DRE1+oh9FxGZS8= 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 4.19 12/49] driver core: Fix probe_count imbalance in really_probe() Date: Mon, 12 Oct 2020 15:26:58 +0200 Message-Id: <20201012132630.006402406@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201012132629.469542486@linuxfoundation.org> References: <20201012132629.469542486@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 @@ -472,7 +472,8 @@ 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: @@ -579,7 +580,7 @@ pinctrl_bind_failed: ret = 0; done: atomic_dec(&probe_count); - wake_up(&probe_waitqueue); + wake_up_all(&probe_waitqueue); return ret; }