From patchwork Wed May 29 17:43:12 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Amir Goldstein X-Patchwork-Id: 10967419 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 060D7933 for ; Wed, 29 May 2019 17:43:48 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EDB3A288DA for ; Wed, 29 May 2019 17:43:47 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E234C28A5E; Wed, 29 May 2019 17:43:47 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8E4AF288DA for ; Wed, 29 May 2019 17:43:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727386AbfE2Rnq (ORCPT ); Wed, 29 May 2019 13:43:46 -0400 Received: from mail-wm1-f67.google.com ([209.85.128.67]:50753 "EHLO mail-wm1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727345AbfE2Rnp (ORCPT ); Wed, 29 May 2019 13:43:45 -0400 Received: by mail-wm1-f67.google.com with SMTP id f204so2264471wme.0; Wed, 29 May 2019 10:43:44 -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:in-reply-to:references; bh=yYTFJKL40LM++VpLTZTzwXvwxxD1UrCsqPZT6tG+/XE=; b=cSqvCgWy1YUQe0dHZNRcbGIm/QEpVxUs6IT3YXaSyTh4x9WjSNR5boI0WRhPgPAwTC YiOR+sZiQ2g335Wkr7SvCOrlFeo8ICtA+/A4NNSnHdOKdDSWWnXG8PDIkjWDzo450BPH iEcy/YGbb+k+IYl//FLQyIIaCWywEu9FP5bLBCJpDzO704xeoNqoCwoLqoNWeelRTvMx aTlXk/0tm4w7OrQ6tcZpAMrsdO/ONgCDJCNZQWiR5retFl7gsuPPehmDMoOE8i9Zrgzo aP+pBNX7yLNjvozjcUMh3FQX+L0lNchxh8e3MP9zvR6pSYznLHLW6k/NYIqE3gNMgS/B 5bcQ== 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:in-reply-to :references; bh=yYTFJKL40LM++VpLTZTzwXvwxxD1UrCsqPZT6tG+/XE=; b=krNgBSOQcjUiqjrVtHXNlvYluzCxCYSaxmalJHYugjo4lQKbRbt4SF75NI9E7hXJSr WA4rxP/7FnEPNjlwI1hPgXJC5jQCQ4/ywIjxXWV2mQ4GuRUK241eJ3usOL2vFJcYcByy 9uTwU2Xi8SjoJFqgtNG38MQLsw/Za5DGSRQEB+IYToul3vyIfSKjQQ7zZyRh5BfGRFYj 3Cg928n+pINQtLeJUHmnUUlZevZJ1Q/57rOWEWNuB2SVcofEQ75sywioYINgiwLaT8Un 6JZ2lysN+GHU3jjoShZU73CBKwgkdSU5pb/Gar+Vh9/4Bi6cXKl7aIe0PN+tF3I9fH/u dywQ== X-Gm-Message-State: APjAAAU7JJpdz3MdGX3JdYKKvWwCWT/OAyL2TOyS7uuJnUbHh0E3TTEl 57OMurvcgWLNf9jBFuE0vXM= X-Google-Smtp-Source: APXvYqwquQoM7yAP2+/AyNykqKSjW4fG5r+voHHnsO1jrH6Riwda2nc9fTFThBKC6BcsinK57kEFVg== X-Received: by 2002:a1c:f60d:: with SMTP id w13mr7438206wmc.40.1559151823589; Wed, 29 May 2019 10:43:43 -0700 (PDT) Received: from localhost.localdomain ([5.102.238.208]) by smtp.gmail.com with ESMTPSA id k125sm31702wmb.34.2019.05.29.10.43.41 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 29 May 2019 10:43:42 -0700 (PDT) From: Amir Goldstein To: "Darrick J . Wong" Cc: Dave Chinner , Christoph Hellwig , linux-xfs@vger.kernel.org, Olga Kornievskaia , Luis Henriques , Al Viro , linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org, ceph-devel@vger.kernel.org, linux-nfs@vger.kernel.org, linux-cifs@vger.kernel.org Subject: [PATCH v3 08/13] vfs: copy_file_range needs to strip setuid bits and update timestamps Date: Wed, 29 May 2019 20:43:12 +0300 Message-Id: <20190529174318.22424-9-amir73il@gmail.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190529174318.22424-1-amir73il@gmail.com> References: <20190529174318.22424-1-amir73il@gmail.com> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Because generic_copy_file_range doesn't hold the destination inode lock throughout the copy, strip setuid bits before and after copy. The destination inode mtime is updated before and after the copy and the source inode atime is updated after the copy, similar to generic_file_read_iter(). Signed-off-by: Amir Goldstein Reviewed-by: Darrick J. Wong --- fs/read_write.c | 23 +++++++++++++++++++++-- 1 file changed, 21 insertions(+), 2 deletions(-) diff --git a/fs/read_write.c b/fs/read_write.c index cec7e7b1f693..706ea5f276a7 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -1590,8 +1590,27 @@ ssize_t generic_copy_file_range(struct file *file_in, loff_t pos_in, struct file *file_out, loff_t pos_out, size_t len, unsigned int flags) { - return do_splice_direct(file_in, &pos_in, file_out, &pos_out, - len > MAX_RW_COUNT ? MAX_RW_COUNT : len, 0); + struct inode *inode_out = file_inode(file_out); + int ret, err; + + /* Should inode_out lock be held throughout the copy operation? */ + inode_lock(inode_out); + err = file_modified(file_out); + inode_unlock(inode_out); + if (err) + return err; + + ret = do_splice_direct(file_in, &pos_in, file_out, &pos_out, + len > MAX_RW_COUNT ? MAX_RW_COUNT : len, 0); + + file_accessed(file_in); + + /* To be on the safe side, remove privs also after copy */ + inode_lock(inode_out); + err = file_modified(file_out); + inode_unlock(inode_out); + + return err ?: ret; } EXPORT_SYMBOL(generic_copy_file_range);