On Thu, 2014-06-12 at 14:59 -0700, Greg KH wrote:
> On Thu, Jun 12, 2014 at 10:10:59PM +0100, Ben Hutchings wrote:
> > On Thu, 2014-06-12 at 14:05 -0700, Greg KH wrote:
> > > On Thu, Jun 12, 2014 at 02:03:23PM -0700, Greg KH wrote:
> > > > On Thu, Jun 12, 2014 at 09:21:41PM +0100, Ben Hutchings wrote:
> > > > > On Thu, 2014-06-12 at 20:36 +0100, Ben Hutchings wrote:
> > > > > > Control: tag -1 security upstream patch moreinfo
> > > > > > Control: severity -1 grave
> > > > > > Control: found -1 3.14.5-1
> > > > >
> > > > > Aurelien Jarno pointed out this appears to be fixed upstream in 3.15:
> > > > >
> > > > > commit 137f7df8cead00688524c82360930845396b8a21
> > > > > Author: Markos Chandras <markos.chandras@imgtec.com>
> > > > > Date: Wed Jan 22 14:40:00 2014 +0000
> > > > >
> > > > > MIPS: asm: thread_info: Add _TIF_SECCOMP flag
> > > > >
> > > > > It looks like this can be cherry-picked cleanly onto stable branches for
> > > > > 3.13 and 3.14. For 3.11 and 3.12, it will need trivial adjustment.
> > > > >
> > > > > For branches older than 3.11, this needs to be cherry-picked first:
> > > > >
> > > > > commit e7f3b48af7be9f8007a224663a5b91340626fed5
> > > > > Author: Ralf Baechle <ralf@linux-mips.org>
> > > > > Date: Wed May 29 01:02:18 2013 +0200
> > > > >
> > > > > MIPS: Cleanup flags in syscall flags handlers.
> > > >
> > > > It also needs parts of 1d7bf993e0731b4ac790667c196b2a2d787f95c3 (MIPS:
> > > > ftrace: Add support for syscall tracepoints.) to apply properly to stuff
> > > > older than 3.11. But, I'm not so sure that is good to apply as that is
> > > > a whole new feature.
> > > >
> > > > So I think I'll just do this "by hand" to get it to work properly...
> > >
> > > Wait, no, SECCOMP for MIPS isn't even in 3.10 or older kernels, so why
> > > is this a 3.2 issue? Did you add it there to your kernel for some
> > > reason?
> >
> > Seccomp mode 2 (i.e. filtering with BPF) was only just implenented for
> > MIPS in 3.15. Mode 1 (fixed set of syscalls) was implemented long ago.
>
> Really? I don't see _TIF_SECCOMP in the mips asm files in 3.10. I
> don't feel comfortable backporting it to 3.10 or 3.4, are you going to
> do that for 3.2?
I'm attaching the backport to 3.2 which I've now been able to test. It
appears to apply cleanly to 3.4 and 3.10 as well. ("MIPS: Cleanup flags
in syscall flags handlers." applies to all branches with some fuzz.)
> > (If prctl(PR_SET_SECCOMP) could return success when CONFIG_SECCOMP is
> > not enabled, that would be even worse!)
>
> True, but this seems to have always been broken, right? :)
Yes, so far as I can see.
Ben.
--
Ben Hutchings
Tomorrow will be cancelled due to lack of interest.
From: Markos Chandras <markos.chandras@imgtec.com> Date: Wed, 22 Jan 2014 14:40:00 +0000 Subject: MIPS: asm: thread_info: Add _TIF_SECCOMP flag Origin: https://git.kernel.org/linus/137f7df8cead00688524c82360930845396b8a21 Add _TIF_SECCOMP flag to _TIF_WORK_SYSCALL_ENTRY to indicate that the system call needs to be checked against a seccomp filter. Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Reviewed-by: Paul Burton <paul.burton@imgtec.com> Reviewed-by: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/6405/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> [bwh: Backported to 3.2: various other flags are not included in _TIF_WORK_SYSCALL_ENTRY] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> --- --- a/arch/mips/include/asm/thread_info.h +++ b/arch/mips/include/asm/thread_info.h @@ -149,7 +149,7 @@ register struct thread_info *__current_t #define _TIF_FPUBOUND (1<<TIF_FPUBOUND) #define _TIF_LOAD_WATCH (1<<TIF_LOAD_WATCH) -#define _TIF_WORK_SYSCALL_ENTRY (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT) +#define _TIF_WORK_SYSCALL_ENTRY (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SECCOMP) /* work to do in syscall_trace_leave() */ #define _TIF_WORK_SYSCALL_EXIT (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT)
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