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=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,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 40212C07E9C for ; Wed, 7 Jul 2021 02:36:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1DF6E61CA2 for ; Wed, 7 Jul 2021 02:36:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229998AbhGGCjI (ORCPT ); Tue, 6 Jul 2021 22:39:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51228 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229894AbhGGCjG (ORCPT ); Tue, 6 Jul 2021 22:39:06 -0400 Received: from mail-pj1-x102f.google.com (mail-pj1-x102f.google.com [IPv6:2607:f8b0:4864:20::102f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 03F78C061574; Tue, 6 Jul 2021 19:36:26 -0700 (PDT) Received: by mail-pj1-x102f.google.com with SMTP id p9so645147pjl.3; Tue, 06 Jul 2021 19:36:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=xCxCbJlJiqNeiIjObMW1i82bs2z6LZMv7wXyXYhR9UY=; b=sKCXnleWWkjorBPJdQcv0RhDEn8XoGWzLD7XBRZ4y+PfdPegQ5aF0qGHwm8gP0hRPN wt1vKhublUX1mPP4zyjlltWW9rxInI0ztJsSMtIJ/AfQ18bu6kV1qow29SZCPxSU4y57 BKyt0JwxRpZ5uYhELLv5Dfzb3tOQLg6b6rDsxUk0bSDSpR+8ksVZQyFRcDJEbc2gTRmt +UhiKP9EzL/jvBBAchlv/i8EekT/OZ0+zf5qL0CECX/fOh1CXZJxKg2tJFyiT/Wnma8Z Br/Ak3G8K6oKWXJDAbHt1YO3mQ/5vhcR2Xwgch8g0KGDHHOsyyB7SWgE8dnMP8nItVSz caTw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=xCxCbJlJiqNeiIjObMW1i82bs2z6LZMv7wXyXYhR9UY=; b=jtzibEmnzC+jNtWyfzqjUe0okNUcikcZhM/oQvbk7dezhHYSJ0r4VlOLmCzJEokIOi YLiD6TkDxj/ka4eB5Yo9Ewm2hkFKL3EPs+W8QfN0zGDIGNTRVgek89Fc5F8PjVOCwZ14 aHsfywipOSBZ+0jjWZKu5uYTdtOPV7Wiz1gHW8Nyk2Jlp9uXTIQ86VuTM/q+i2SY+97V zZRk9SQyVrMkPDqzD+9yd/vc1mQJVvVNgMEAXTjNJf0u/FueDJlp2LUhqCQtWPiCJSuh L5f43FuDK/jldouAaOw3wOfNWwSWqZrbK3IXFDfVHnuwTSlzwgMzA3B4PIH5h+y+lRSZ MH8w== X-Gm-Message-State: AOAM530/baI8V7KHUDH9M7T40W+EwsfyQ9FmJTSFG13t1lf9ZXZz2vGq +nhBVgD9OotOTchyE8OM3lg= X-Google-Smtp-Source: ABdhPJzhZho7v0iBKzVWkaCF+D5/fnmu0nCJ1sZyZl+vvZighIoY9emIsRGfaHg7xD4w97d7jSMMDA== X-Received: by 2002:a17:902:ff13:b029:129:9a0b:c2dc with SMTP id f19-20020a170902ff13b02901299a0bc2dcmr8341242plj.45.1625625385504; Tue, 06 Jul 2021 19:36:25 -0700 (PDT) Received: from localhost.localdomain ([118.200.190.93]) by smtp.gmail.com with ESMTPSA id r14sm20589446pgm.28.2021.07.06.19.36.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 06 Jul 2021 19:36:25 -0700 (PDT) From: Desmond Cheong Zhi Xi To: jlayton@kernel.org, bfields@fieldses.org, viro@zeniv.linux.org.uk Cc: Desmond Cheong Zhi Xi , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, skhan@linuxfoundation.org, gregkh@linuxfoundation.org, linux-kernel-mentees@lists.linuxfoundation.org Subject: [PATCH v2 0/2] fcntl: fix potential deadlocks Date: Wed, 7 Jul 2021 10:35:46 +0800 Message-Id: <20210707023548.15872-1-desmondcheongzx@gmail.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Sorry for the delay between v1 and v2, there was an unrelated issue with Syzbot testing. Syzbot reports a possible irq lock inversion dependency: https://syzkaller.appspot.com/bug?id=923cfc6c6348963f99886a0176ef11dcc429547b While investigating this error, I discovered that multiple similar lock inversion scenarios can occur. Hence, this series addresses potential deadlocks for two classes of locks, one in each patch: 1. Fix potential deadlocks for &fown_struct.lock 2. Fix potential deadlock for &fasync_struct.fa_lock v1 -> v2: - Added WARN_ON_ONCE(irqs_disabled()) before calls to read_lock_irq, with elaboration in the commit message, as suggested by Jeff Layton. Best wishes, Desmond Desmond Cheong Zhi Xi (2): fcntl: fix potential deadlocks for &fown_struct.lock fcntl: fix potential deadlock for &fasync_struct.fa_lock fs/fcntl.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) -- 2.25.1