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=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL 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 68D50C43460 for ; Mon, 12 Apr 2021 18:09:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 395F461357 for ; Mon, 12 Apr 2021 18:09:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241789AbhDLSJb (ORCPT ); Mon, 12 Apr 2021 14:09:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46748 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244402AbhDLSJ3 (ORCPT ); Mon, 12 Apr 2021 14:09:29 -0400 Received: from mail-qv1-xf4a.google.com (mail-qv1-xf4a.google.com [IPv6:2607:f8b0:4864:20::f4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 455CDC061756 for ; Mon, 12 Apr 2021 11:09:11 -0700 (PDT) Received: by mail-qv1-xf4a.google.com with SMTP id r14so6274955qvr.14 for ; Mon, 12 Apr 2021 11:09:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=YHUvegXTW3ogsW2Kd44BTYx7zYoANC3O5F45o7xWFi0=; b=BmTDC/pUmDJaIZgYDDtwLGGgzkDW+UKPr6oQQT3APLdLVPjFO+haGDg20O4owKZzPR WMryUydfGwu9rcZZJgNoCFtlVl/GtkhPZwmWXvNLgzSLqqhQWFaExfW5Wz4bexQNH70Y 5Z7T5LQAYbdoexQRpZO/NzboaPbhi5GFli1P39t0hYNjsygx5Git5wQ54EfSjxE41Kk4 zix/hPA+ILLWx4iOyiKMdfT6vyzgQlrLJX4e1CwLPhDe7fI53GXwS7/0Aim1E7YQHfeU IlHhoTOxahkqWPrZE7jMhy2sugTG7+E+PCm6K8teTqJ4BvIy3BRjxicPWGe/7lvF2ih8 NQJA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=YHUvegXTW3ogsW2Kd44BTYx7zYoANC3O5F45o7xWFi0=; b=FI/gpZU+4OoaijJ2OXqlGaCZQneQNF2h7XI6bIk5i8D1aa48Qhh5yCTcCw/6nJgmpF hcNlWPLpnZ9swZh+zlCmHK4YXg3LUTqDnH2zHxBqzC0mvsp7OMpwuDo1nhnRY/vRjRR+ P4o/j7krV+yGy4oRNCu5yVD/zkpJTsw8gpzI+T3qyWJp4RKh7pgU9VT3xzjTm5nC6vW8 5j4CGOTE1WZpz8qm1av342o3mBKqzNiIwAasmJNHnZTH7gWWb+dsk86k+p/v8LfjhXUZ P8G41hm8etBTGQ1J+lGYBJLh6QYYdcuJkHFiQ64wFDUjYqbn04l7oTZa/IDyZhVwXFCL bGXg== X-Gm-Message-State: AOAM532MIHl3eLUkravnjtsYwFtbW+ZPlIaWknVVXrgmTVx2IQHlI/gR PMJnmkafGZ6TbO8hK/lc3XlCvZMPS0q9twQ= X-Google-Smtp-Source: ABdhPJzIZ4Fz4rwkHcYXl0FnDvoa1lIX0Bo487av5cQ/BXnBwD3n0FCf6A+SpqyaHHutkoLia+aCdGyPNyicjAA= X-Received: from saravanak.san.corp.google.com ([2620:15c:2d:3:951b:6a90:74:1cd1]) (user=saravanak job=sendgmr) by 2002:a0c:fc12:: with SMTP id z18mr5225480qvo.38.1618250950335; Mon, 12 Apr 2021 11:09:10 -0700 (PDT) Date: Mon, 12 Apr 2021 11:09:06 -0700 Message-Id: <20210412180907.1980874-1-saravanak@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.31.1.295.g9ea45b61b8-goog Subject: [PATCH] driver core: Fix locking bug in deferred_probe_timeout_work_func() From: Saravana Kannan To: Greg Kroah-Hartman , "Rafael J. Wysocki" Cc: Saravana Kannan , stable@vger.kernel.org, kernel-team@android.com, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org commit eed6e41813deb9ee622cd9242341f21430d7789f upstream. list_for_each_entry_safe() is only useful if we are deleting nodes in a linked list within the loop. It doesn't protect against other threads adding/deleting nodes to the list in parallel. We need to grab deferred_probe_mutex when traversing the deferred_probe_pending_list. Cc: stable@vger.kernel.org Fixes: 25b4e70dcce9 ("driver core: allow stopping deferred probe after init") Signed-off-by: Saravana Kannan Link: https://lore.kernel.org/r/20210402040342.2944858-2-saravanak@google.com Signed-off-by: Greg Kroah-Hartman --- Hi Greg, This should apply cleanly to 4.19 and 5.4 if you think this should be picked up. -Saravana drivers/base/dd.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/base/dd.c b/drivers/base/dd.c index 4ba9231a6be8..26ba7a99b7d5 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -254,14 +254,16 @@ int driver_deferred_probe_check_state(struct device *dev) static void deferred_probe_timeout_work_func(struct work_struct *work) { - struct device_private *private, *p; + struct device_private *p; deferred_probe_timeout = 0; driver_deferred_probe_trigger(); flush_work(&deferred_probe_work); - list_for_each_entry_safe(private, p, &deferred_probe_pending_list, deferred_probe) - dev_info(private->device, "deferred probe pending"); + mutex_lock(&deferred_probe_mutex); + list_for_each_entry(p, &deferred_probe_pending_list, deferred_probe) + dev_info(p->device, "deferred probe pending\n"); + mutex_unlock(&deferred_probe_mutex); } static DECLARE_DELAYED_WORK(deferred_probe_timeout_work, deferred_probe_timeout_work_func); -- 2.31.1.295.g9ea45b61b8-goog