Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753907AbaATRPp (ORCPT ); Mon, 20 Jan 2014 12:15:45 -0500 Received: from smtp3-g21.free.fr ([212.27.42.3]:48805 "EHLO smtp3-g21.free.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751740AbaATRPn (ORCPT ); Mon, 20 Jan 2014 12:15:43 -0500 Message-ID: <1390238130.3865.20.camel@localhost.localdomain> Subject: Re: [PATCHv5 5/7] fanotify: enable close-on-exec on events' fd when requested in fanotify_init() From: Yann Droneaud To: Lino Sanfilippo Cc: linux-kernel@vger.kernel.org, Eric Paris , Al Viro , Andrew Morton Date: Mon, 20 Jan 2014 18:15:30 +0100 In-Reply-To: <3d9591f81e62a78a726721c8052b3910870db35e.1388952061.git.ydroneaud@opteya.com> References: <3d9591f81e62a78a726721c8052b3910870db35e.1388952061.git.ydroneaud@opteya.com> Organization: OPTEYA Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.10.3 (3.10.3-1.fc20) Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Lino, I've recently sent this patch which may fix a bug in the way fanotify creates its file descriptors. I failed to noticed you've been working recently on fanotify subsystem and miss the opportunity to add you in the Cc:s. Please have a look to this patch and help to get it merged. Le dimanche 05 janvier 2014 à 21:36 +0100, Yann Droneaud a écrit : > According to commit 80af258867648, file descriptor created as part > of file access notification events inherit flags from the event_f_flags > argument passed to syscall fanotify_init(2). > > So while it is legal for userspace to call fanotify_init() with O_CLOEXEC > as part of its second argument, O_CLOEXEC is currently silently ignored. > > Indeed event_f_flags are only given to dentry_open(), which only > seems to care about O_ACCMODE and O_PATH in do_dentry_open(), O_DIRECT > in open_check_o_direct() and O_LARGEFILE in generic_file_open(). > > More, there's no effective check on event_f_flags value that would > catch unknown / unsupported values, unlike the one on f_flags argument > of the syscall (see FAN_ALL_INIT_FLAGS in include/uapi/linux/fanotify.h). ... > But it seems logical to set close-on-exec flag on the file descriptor > if userspace is allowed to request it with O_CLOEXEC. > ... > So this patch replaces call to macro get_unused_fd() by a call to > function get_unused_fd_flags() with event_f_flags value as argument. > This way O_CLOEXEC flag in the second argument of fanotify_init(2) > syscall is interpreted so that close-on-exec get enabled. ... > Cc: Eric Paris > Cc: Al Viro > Cc: stable@vger.kernel.org > Signed-off-by: Yann Droneaud > Link: > http://lkml.kernel.org/r/cover.1388952061.git.ydroneaud@opteya.com > > --- > fs/notify/fanotify/fanotify_user.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c > index 57d7c083cb4b..6d0eaabba02e 100644 > --- a/fs/notify/fanotify/fanotify_user.c > +++ b/fs/notify/fanotify/fanotify_user.c > @@ -71,7 +71,7 @@ static int create_fd(struct fsnotify_group *group, > > pr_debug("%s: group=%p event=%p\n", __func__, group, event); > > - client_fd = get_unused_fd(); > + client_fd = get_unused_fd_flags(group->fanotify_data.f_flags); > if (client_fd < 0) > return client_fd; > Regards. -- Yann Droneaud OPTEYA -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/