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 29418C433E7 for ; Mon, 12 Oct 2020 13:58:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D4C6F206FB for ; Mon, 12 Oct 2020 13:58:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602511105; bh=GRmaemHNO56jxAAxfhtxvLRBCsKt9NA3rAsCZsZQ544=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=gwD1EHwdk9dHJxGT/V4L0YfQLmHQlnZsj8zVSrcF3vtoinntKKxm+djeeixoREKHU 9DGQ+Vo9//qxCz0KyRsJCKKIYbNQW3+JEKV7ve7aZxfGK7YbYf2EKJiwradquDq+Ma +NoXgGRSfrwt2XO2HNUTtxkDa+UfD2XIdjgEva24= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389365AbgJLN6Y (ORCPT ); Mon, 12 Oct 2020 09:58:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:43908 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731481AbgJLNk6 (ORCPT ); Mon, 12 Oct 2020 09:40:58 -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 274EE22260; Mon, 12 Oct 2020 13:40:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602510053; bh=GRmaemHNO56jxAAxfhtxvLRBCsKt9NA3rAsCZsZQ544=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vSluG8OCXEen5vFJEH6IZrg8/vnvUEKSXRfRZ94CTEIhAEskedvGZSva4X0gt9hBy fOe1GH4Lbl2c2XOOqV6aPcV9ryw2CsdYOarKXsiIuFN34uHZYNZNL3LxMzGalDSNcf 67nzm1e11IcLLjV1A8B6Vxz7meAzGt9SOsctmlb8= 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 5.4 21/85] driver core: Fix probe_count imbalance in really_probe() Date: Mon, 12 Oct 2020 15:26:44 +0200 Message-Id: <20201012132633.870032032@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201012132632.846779148@linuxfoundation.org> References: <20201012132632.846779148@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 @@ -518,7 +518,8 @@ 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: @@ -639,7 +640,7 @@ pinctrl_bind_failed: ret = 0; done: atomic_dec(&probe_count); - wake_up(&probe_waitqueue); + wake_up_all(&probe_waitqueue); return ret; }