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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8901EC072A2 for ; Tue, 14 Nov 2023 15:33:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233678AbjKNPdT (ORCPT ); Tue, 14 Nov 2023 10:33:19 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51750 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233687AbjKNPdS (ORCPT ); Tue, 14 Nov 2023 10:33:18 -0500 Received: from mail-wm1-x32b.google.com (mail-wm1-x32b.google.com [IPv6:2a00:1450:4864:20::32b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AA16793 for ; Tue, 14 Nov 2023 07:33:14 -0800 (PST) Received: by mail-wm1-x32b.google.com with SMTP id 5b1f17b1804b1-4083f61322fso44964775e9.1 for ; Tue, 14 Nov 2023 07:33:14 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1699975993; x=1700580793; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=iTeM1dBsqSMrj7dJ0Y7ppqb+rwjsKONfTRk0U9DB+v8=; b=iE50zYivMhmkgyuw3Q20x3oLv+eHedCphfBR9VNOOj5zRFtZOwQWxycEpnrYKMVQbz //tbywbPolclSi1SPHrbzJJabynG+CcEBjyGhmh6NtHFqt15eE+X0pnWbxN4sjB81OIu tVyhOiv9ylfeTc6XCBWApYT2p2NL+2hgA8htMykAxRp7ynxwmr84ZDhCL0fPE7T6vY2A Y9No04Bp0OitzHglYAptgyVHJxAVd8YIkMalvcuONPik2QWBcOkI6GMfD/Ucp3zcirb6 dlsShknJz+jjE/+zAiVZ6Du5rz5wWLM+zYLobR88iemqpCXlkTDu25mjHrhkRcRyQkKP P6Ew== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1699975993; x=1700580793; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=iTeM1dBsqSMrj7dJ0Y7ppqb+rwjsKONfTRk0U9DB+v8=; b=BsUbzTtFIE6tw71eEjBqQZPt9r3HTyqbGDLFPS7YKeUEnhMr6kToCHaHybTeFNwJUW 48XHTFIOmMf0HFHxYIxmoabFrb0PdEtgZrxfTJ7X8AbIWDSvgEpNkxjCXr0NMGbWgPtV AcmdCHpx0UJ3cntXPj40u47/Njlimk8iNgBHHhtMwh+S9mziEVWgfTqCc1+VjmwmFtKw GKCqW/NO8hghVuJO+E30/YGy0hHG1hB8CGP5Wj6lGNFYeoMi9FpJhrdpcg2lJzXoZn5G /4050rvr6Kexmw9cA6CK5AQTB/8z87eiT+5J5bRsM0cQ66ThVLV0Mu4GTbPAMo/ZVQgi X/tA== X-Gm-Message-State: AOJu0Yx/rnvJjR5F40gtOlqEdRdK8ZKgmFuzbBrWcZdCN9oczvErfLdT kjL23vbKyLMkIIlOshLz73s= X-Google-Smtp-Source: AGHT+IGmVy7NRUhi42hrv8qJabpyLF8paXwjwXSvAJuZdJSeVHDgu+vFBvj2IOQbjKCYzXobOy4I3Q== X-Received: by 2002:a05:600c:470a:b0:404:f9c1:d5d7 with SMTP id v10-20020a05600c470a00b00404f9c1d5d7mr7500023wmo.25.1699975993123; Tue, 14 Nov 2023 07:33:13 -0800 (PST) Received: from amir-ThinkPad-T480.lan ([5.29.249.86]) by smtp.gmail.com with ESMTPSA id i10-20020a05600c354a00b004053e9276easm17824505wmq.32.2023.11.14.07.33.11 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 14 Nov 2023 07:33:12 -0800 (PST) From: Amir Goldstein To: Miklos Szeredi Cc: Christian Brauner , linux-unionfs@vger.kernel.org, Jan Kara Subject: [PATCH 10/15] fs: move permission hook out of do_iter_write() Date: Tue, 14 Nov 2023 17:32:49 +0200 Message-Id: <20231114153254.1715969-11-amir73il@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231114153254.1715969-1-amir73il@gmail.com> References: <20231114153254.1715969-1-amir73il@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-unionfs@vger.kernel.org In many of the vfs helpers, the rw_verity_area() checks are called before taking sb_start_write(), making them "start-write-safe". do_iter_write() is an exception to this rule. do_iter_write() has two callers - vfs_iter_write() and vfs_writev(). Move rw_verify_area() and other checks from do_iter_write() out to its callers to make them "start-write-safe". Move also the fsnotify_modify() hook to align with similar pattern used in vfs_write() and other vfs helpers. This is needed for fanotify "pre content" events. Suggested-by: Jan Kara Signed-off-by: Amir Goldstein --- fs/read_write.c | 76 ++++++++++++++++++++++++++++++------------------- 1 file changed, 46 insertions(+), 30 deletions(-) diff --git a/fs/read_write.c b/fs/read_write.c index 8cdc6e6a9639..d4891346d42e 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -848,28 +848,10 @@ EXPORT_SYMBOL(vfs_iter_read); static ssize_t do_iter_write(struct file *file, struct iov_iter *iter, loff_t *pos, rwf_t flags) { - size_t tot_len; - ssize_t ret = 0; - - if (!(file->f_mode & FMODE_WRITE)) - return -EBADF; - if (!(file->f_mode & FMODE_CAN_WRITE)) - return -EINVAL; - - tot_len = iov_iter_count(iter); - if (!tot_len) - return 0; - ret = rw_verify_area(WRITE, file, pos, tot_len); - if (ret < 0) - return ret; - if (file->f_op->write_iter) - ret = do_iter_readv_writev(file, iter, pos, WRITE, flags); + return do_iter_readv_writev(file, iter, pos, WRITE, flags); else - ret = do_loop_readv_writev(file, iter, pos, WRITE, flags); - if (ret > 0) - fsnotify_modify(file); - return ret; + return do_loop_readv_writev(file, iter, pos, WRITE, flags); } ssize_t vfs_iocb_iter_write(struct file *file, struct kiocb *iocb, @@ -903,13 +885,28 @@ EXPORT_SYMBOL(vfs_iocb_iter_write); ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos, rwf_t flags) { - int ret; + size_t tot_len; + ssize_t ret; + if (!(file->f_mode & FMODE_WRITE)) + return -EBADF; + if (!(file->f_mode & FMODE_CAN_WRITE)) + return -EINVAL; if (!file->f_op->write_iter) return -EINVAL; + tot_len = iov_iter_count(iter); + if (!tot_len) + return 0; + + ret = rw_verify_area(WRITE, file, ppos, tot_len); + if (ret < 0) + return ret; + file_start_write(file); ret = do_iter_write(file, iter, ppos, flags); + if (ret > 0) + fsnotify_modify(file); file_end_write(file); return ret; @@ -934,20 +931,39 @@ static ssize_t vfs_readv(struct file *file, const struct iovec __user *vec, } static ssize_t vfs_writev(struct file *file, const struct iovec __user *vec, - unsigned long vlen, loff_t *pos, rwf_t flags) + unsigned long vlen, loff_t *pos, rwf_t flags) { struct iovec iovstack[UIO_FASTIOV]; struct iovec *iov = iovstack; struct iov_iter iter; - ssize_t ret; + size_t tot_len; + ssize_t ret = 0; - ret = import_iovec(ITER_SOURCE, vec, vlen, ARRAY_SIZE(iovstack), &iov, &iter); - if (ret >= 0) { - file_start_write(file); - ret = do_iter_write(file, &iter, pos, flags); - file_end_write(file); - kfree(iov); - } + if (!(file->f_mode & FMODE_WRITE)) + return -EBADF; + if (!(file->f_mode & FMODE_CAN_WRITE)) + return -EINVAL; + + ret = import_iovec(ITER_SOURCE, vec, vlen, ARRAY_SIZE(iovstack), &iov, + &iter); + if (ret < 0) + return ret; + + tot_len = iov_iter_count(&iter); + if (!tot_len) + goto out; + + ret = rw_verify_area(WRITE, file, pos, tot_len); + if (ret < 0) + goto out; + + file_start_write(file); + ret = do_iter_write(file, &iter, pos, flags); + if (ret > 0) + fsnotify_modify(file); + file_end_write(file); +out: + kfree(iov); return ret; } -- 2.34.1