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 <[email protected]> > Cc: Al Viro <[email protected]> > Cc: [email protected] > Signed-off-by: Yann Droneaud <[email protected]> > Link: > http://lkml.kernel.org/r/[email protected] > > --- > 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 [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
