From patchwork Thu Oct 14 21:36:40 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gabriel Krisman Bertazi X-Patchwork-Id: 12559475 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 934CAC433EF for ; Thu, 14 Oct 2021 21:39:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7FF586108B for ; Thu, 14 Oct 2021 21:39:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234034AbhJNVll (ORCPT ); Thu, 14 Oct 2021 17:41:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53418 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233240AbhJNVll (ORCPT ); Thu, 14 Oct 2021 17:41:41 -0400 Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e3e3]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CEE29C061570; Thu, 14 Oct 2021 14:39:35 -0700 (PDT) Received: from localhost (unknown [IPv6:2804:14c:124:8a08::1007]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: krisman) by bhuna.collabora.co.uk (Postfix) with ESMTPSA id 17D671F44F8C; Thu, 14 Oct 2021 22:39:33 +0100 (BST) From: Gabriel Krisman Bertazi To: jack@suse.com, amir73il@gmail.com Cc: djwong@kernel.org, tytso@mit.edu, dhowells@redhat.com, khazhy@google.com, linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-api@vger.kernel.org, repnop@google.com, Gabriel Krisman Bertazi , kernel@collabora.com Subject: [PATCH v7 22/28] fanotify: Report FID entry even for zero-length file_handle Date: Thu, 14 Oct 2021 18:36:40 -0300 Message-Id: <20211014213646.1139469-23-krisman@collabora.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20211014213646.1139469-1-krisman@collabora.com> References: <20211014213646.1139469-1-krisman@collabora.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Non-inode errors will reported with an empty file_handle. In preparation for that, allow some events to print the FID record even if there isn't any file_handle encoded Even though FILEID_ROOT is used internally, make zero-length file handles be reported as FILEID_INVALID. Signed-off-by: Gabriel Krisman Bertazi --- fs/notify/fanotify/fanotify_user.c | 23 ++++++++++++++++++----- 1 file changed, 18 insertions(+), 5 deletions(-) diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c index 5324890500fc..39cf8ba4a6ce 100644 --- a/fs/notify/fanotify/fanotify_user.c +++ b/fs/notify/fanotify/fanotify_user.c @@ -127,6 +127,16 @@ static int fanotify_fid_info_len(int fh_len, int name_len) FANOTIFY_EVENT_ALIGN); } +static bool fanotify_event_allows_empty_fh(struct fanotify_event *event) +{ + switch (event->type) { + case FANOTIFY_EVENT_TYPE_FS_ERROR: + return true; + default: + return false; + } +} + static size_t fanotify_event_len(unsigned int info_mode, struct fanotify_event *event) { @@ -157,7 +167,7 @@ static size_t fanotify_event_len(unsigned int info_mode, if (info_mode & FAN_REPORT_PIDFD) event_len += FANOTIFY_PIDFD_INFO_HDR_LEN; - if (fh_len) + if (fh_len || fanotify_event_allows_empty_fh(event)) event_len += fanotify_fid_info_len(fh_len, dot_len); return event_len; @@ -338,9 +348,6 @@ static int copy_fid_info_to_user(__kernel_fsid_t *fsid, struct fanotify_fh *fh, pr_debug("%s: fh_len=%zu name_len=%zu, info_len=%zu, count=%zu\n", __func__, fh_len, name_len, info_len, count); - if (!fh_len) - return 0; - if (WARN_ON_ONCE(len < sizeof(info) || len > count)) return -EFAULT; @@ -375,6 +382,11 @@ static int copy_fid_info_to_user(__kernel_fsid_t *fsid, struct fanotify_fh *fh, handle.handle_type = fh->type; handle.handle_bytes = fh_len; + + /* Mangle handle_type for bad file_handle */ + if (!fh_len) + handle.handle_type = FILEID_INVALID; + if (copy_to_user(buf, &handle, sizeof(handle))) return -EFAULT; @@ -467,7 +479,8 @@ static int copy_info_records_to_user(struct fanotify_event *event, total_bytes += ret; } - if (fanotify_event_object_fh_len(event)) { + if (fanotify_event_object_fh_len(event) || + fanotify_event_allows_empty_fh(event)) { const char *dot = NULL; int dot_len = 0;