From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oren Laadan Subject: Re: [RFC][v8][PATCH 7/10]: Check invalid clone flags Date: Tue, 13 Oct 2009 14:35:57 -0400 Message-ID: <4AD4C88D.7040008@librato.com> References: <20091013044925.GA28181@us.ibm.com> <20091013045234.GG28435@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20091013045234.GG28435-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Sukadev Bhattiprolu Cc: randy.dunlap-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org, arnd-r2nGTMty4D4@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Containers , Nathan Lynch , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Louis.Rilling-aw0BnHfMbSpBDgjK7y7TUQ@public.gmane.org, "Eric W. Biederman" , kosaki.motohiro-+CUm20s59erQFUHtdCDX3A@public.gmane.org, hpa-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org, mingo-X9Un+BFzKDI@public.gmane.org, torvalds-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, Alexey Dobriyan , roland-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, Pavel Emelyanov List-Id: linux-api@vger.kernel.org Sukadev Bhattiprolu wrote: > > Subject: [RFC][v8][PATCH 7/10]: Check invalid clone flags > > As pointed out by Oren Laadan, we want to ensure that unused bits in the > clone-flags remain unused and available for future. To ensure this, define > a mask of clone-flags and check the flags in the clone() system calls. > > Changelog[v8]: > - New patch in set > > Signed-off-by: Sukadev Bhattiprolu > > --- > include/linux/sched.h | 10 ++++++++++ > kernel/fork.c | 3 +++ > 2 files changed, 13 insertions(+) > > Index: linux-2.6/include/linux/sched.h > =================================================================== > --- linux-2.6.orig/include/linux/sched.h 2009-10-02 18:53:55.000000000 -0700 > +++ linux-2.6/include/linux/sched.h 2009-10-02 19:58:21.000000000 -0700 > @@ -29,6 +29,16 @@ > #define CLONE_NEWNET 0x40000000 /* New network namespace */ > #define CLONE_IO 0x80000000 /* Clone io context */ > > +#define VALID_CLONE_FLAGS (CSIGNAL | CLONE_VM | CLONE_FS | CLONE_FILES |\ > + CLONE_SIGHAND | CLONE_PTRACE | CLONE_VFORK |\ > + CLONE_PARENT | CLONE_THREAD | CLONE_NEWNS |\ > + CLONE_SYSVSEM | CLONE_SETTLS |\ > + CLONE_PARENT_SETTID | CLONE_CHILD_CLEARTID |\ > + CLONE_DETACHED | CLONE_UNTRACED |\ > + CLONE_CHILD_SETTID | CLONE_STOPPED |\ > + CLONE_NEWUTS | CLONE_NEWIPC | CLONE_NEWUSER |\ > + CLONE_NEWPID | CLONE_NEWNET| CLONE_IO) > + > /* > * Scheduling policies > */ > Index: linux-2.6/kernel/fork.c > =================================================================== > --- linux-2.6.orig/kernel/fork.c 2009-10-02 19:00:08.000000000 -0700 > +++ linux-2.6/kernel/fork.c 2009-10-02 19:57:36.000000000 -0700 > @@ -942,6 +942,9 @@ static struct task_struct *copy_process( > struct task_struct *p; > int cgroup_callbacks_done = 0; > We can safely apply these tests to clone3(), because it is a new syscall. However, I don't know if applying it to clone() can break existing application that may already be (incorrectly) using invalid flags ? Oren. > + if (clone_flags & ~VALID_CLONE_FLAGS) > + return ERR_PTR(-EINVAL); > + > if ((clone_flags & (CLONE_NEWNS|CLONE_FS)) == (CLONE_NEWNS|CLONE_FS)) > return ERR_PTR(-EINVAL); > > _______________________________________________ > Containers mailing list > Containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org > https://lists.linux-foundation.org/mailman/listinfo/containers