From patchwork Fri May 8 09:22:12 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 11536129 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 65288913 for ; Fri, 8 May 2020 09:23:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 41AFE21582 for ; Fri, 8 May 2020 09:23:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="O9BYEco6" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726843AbgEHJW2 (ORCPT ); Fri, 8 May 2020 05:22:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56518 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726746AbgEHJW1 (ORCPT ); Fri, 8 May 2020 05:22:27 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CA2C6C05BD43; Fri, 8 May 2020 02:22:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=xPhGP2jiYAjHpxSk/ggsWDYG1ptmeqnodXQwagIjz80=; b=O9BYEco6eWqsAs1PWLYmxNpjmD PoBKDzzLadPZjumipcrGt30j682jPS2N/LZPgAjG+d9zE7N64mb9uCLbtiC1w0iSlPNe4pHCebO9J ucCuOlaBfVYZPQ9xMintsgxB3rniNoIJPGggd5MGpbFnGdD8R0JnTVnRa9bt/5C/5036+UID/T3mk dS69zQ2VmCyxnm2Kk6pB3iTZDO3ddwPfeHSrh6Vhj/gNcSUJpttTphD4m9/pRK0ZKO5mdeBscV8AH Ow2hy6r/9QNcOKCd/xVixYFQcSeOEWmZ7zZK+tLbWQE+kZ2ueXryc5miatQD0NAdu+j0jmzAvzqjH 5Gn3wVYQ==; Received: from [2001:4bb8:180:9d3f:90d7:9df8:7cd:3504] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jWzD9-0008Ii-AY; Fri, 08 May 2020 09:22:27 +0000 From: Christoph Hellwig To: Al Viro Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-security-module@vger.kernel.org Subject: [PATCH 01/11] fs: call file_{start,end}_write from __kernel_write Date: Fri, 8 May 2020 11:22:12 +0200 Message-Id: <20200508092222.2097-2-hch@lst.de> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200508092222.2097-1-hch@lst.de> References: <20200508092222.2097-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: We always need to take a reference on the file system we are writing to. Signed-off-by: Christoph Hellwig --- fs/read_write.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/read_write.c b/fs/read_write.c index bbfa9b12b15eb..d5aaf3a4198b9 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -508,6 +508,7 @@ ssize_t __kernel_write(struct file *file, const void *buf, size_t count, loff_t if (!(file->f_mode & FMODE_CAN_WRITE)) return -EINVAL; + file_start_write(file); old_fs = get_fs(); set_fs(KERNEL_DS); p = (__force const char __user *)buf; @@ -520,6 +521,7 @@ ssize_t __kernel_write(struct file *file, const void *buf, size_t count, loff_t add_wchar(current, ret); } inc_syscw(current); + file_end_write(file); return ret; } EXPORT_SYMBOL(__kernel_write);