From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oren Laadan Subject: Re: [v9][PATCH 6/9] Check invalid clone flags Date: Sun, 25 Oct 2009 13:08:16 -0400 Message-ID: <4AE48600.8030800@librato.com> References: <20091025033508.GA20327@us.ibm.com> <20091025033937.GG20327@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20091025033937.GG20327-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Sukadev Bhattiprolu Cc: Andrew Morton , randy.dunlap-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org, mtk.manpages-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org, pavel-+ZI9xUNit7I@public.gmane.org, hpa-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org, Pavel Emelyanov , Louis.Rilling-aw0BnHfMbSpBDgjK7y7TUQ@public.gmane.org, kosaki.motohiro-+CUm20s59erQFUHtdCDX3A@public.gmane.org, mingo-X9Un+BFzKDI@public.gmane.org, Alexey Dobriyan , "Eric W. Biederman" , arnd-r2nGTMty4D4@public.gmane.org, Nathan Lynch , roland-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Containers , torvalds-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org List-Id: linux-api@vger.kernel.org Sukadev Bhattiprolu wrote: > Subject: [v9][PATCH 6/9] 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[v9]: > - Include the unused clone-flag (CLONE_UNUSED) to VALID_CLONE_FLAGS > to avoid breaking any applications that may have set it. IOW, this > patch/check only applies to clone-flags bits 33 and higher. > > Changelog[v8]: > - New patch in set > > Signed-off-by: Sukadev Bhattiprolu Acked-by: Oren Laadan > --- > include/linux/sched.h | 12 ++++++++++++ > kernel/fork.c | 3 +++ > 2 files changed, 15 insertions(+), 0 deletions(-) > > diff --git a/include/linux/sched.h b/include/linux/sched.h > index 75e6e60..6b319a0 100644 > --- a/include/linux/sched.h > +++ b/include/linux/sched.h > @@ -29,6 +29,18 @@ > #define CLONE_NEWNET 0x40000000 /* New network namespace */ > #define CLONE_IO 0x80000000 /* Clone io context */ > > +#define CLONE_UNUSED 0x00001000 /* Can be reused ? */ > + > +#define VALID_CLONE_FLAGS (CSIGNAL | CLONE_VM | CLONE_FS | CLONE_FILES |\ > + CLONE_SIGHAND | CLONE_UNUSED | 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 > */ > diff --git a/kernel/fork.c b/kernel/fork.c > index c8a06de..11f77ed 100644 > --- a/kernel/fork.c > +++ b/kernel/fork.c > @@ -982,6 +982,9 @@ static struct task_struct *copy_process(unsigned long clone_flags, > struct task_struct *p; > int cgroup_callbacks_done = 0; > > + 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); >