From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vlad Yasevich Subject: Re: [PATCH 12/13] sctp: use get_unused_fd_flags(0) instead of get_unused_fd() Date: Tue, 02 Jul 2013 13:50:32 -0400 Message-ID: <51D312E8.6090702@gmail.com> References: <6d4271e2e0b05ae2728cba1d890e77cac50cf8f0.1372777600.git.ydroneaud@opteya.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: linux-kernel@vger.kernel.org, linux-sctp@vger.kernel.org, netdev@vger.kernel.org To: Yann Droneaud Return-path: Received: from mail-vc0-f177.google.com ([209.85.220.177]:60375 "EHLO mail-vc0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752060Ab3GBRug (ORCPT ); Tue, 2 Jul 2013 13:50:36 -0400 In-Reply-To: <6d4271e2e0b05ae2728cba1d890e77cac50cf8f0.1372777600.git.ydroneaud@opteya.com> Sender: netdev-owner@vger.kernel.org List-ID: On 07/02/2013 12:39 PM, Yann Droneaud wrote: > Macro get_unused_fd() is used to allocate a file descriptor with > default flags. Those default flags (0) can be "unsafe": > O_CLOEXEC must be used by default to not leak file descriptor > across exec(). > > Instead of macro get_unused_fd(), functions anon_inode_getfd() > or get_unused_fd_flags() should be used with flags given by userspace. > If not possible, flags should be set to O_CLOEXEC to provide userspace > with a default safe behavor. > > In a further patch, get_unused_fd() will be removed so that > new code start using anon_inode_getfd() or get_unused_fd_flags() > with correct flags. > > This patch replaces calls to get_unused_fd() with equivalent call to > get_unused_fd_flags(0) to preserve current behavor for existing code. > > The hard coded flag value (0) should be reviewed on a per-subsystem basis, > and, if possible, set to O_CLOEXEC. > > Signed-off-by: Yann Droneaud Acked-by: Vlad Yasevich -vlad > --- > net/sctp/socket.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/sctp/socket.c b/net/sctp/socket.c > index 66fcdcf..caa5919 100644 > --- a/net/sctp/socket.c > +++ b/net/sctp/socket.c > @@ -4320,7 +4320,7 @@ static int sctp_getsockopt_peeloff(struct sock *sk, int len, char __user *optval > goto out; > > /* Map the socket to an unused fd that can be returned to the user. */ > - retval = get_unused_fd(); > + retval = get_unused_fd_flags(0); > if (retval < 0) { > sock_release(newsock); > goto out; >