* [WARNING] x86/mm: Found insecure W+X mapping at address ..
@ 2017-05-23 15:40 Thomas Gleixner
2017-05-23 15:54 ` Kees Cook
0 siblings, 1 reply; 6+ messages in thread
From: Thomas Gleixner @ 2017-05-23 15:40 UTC (permalink / raw)
To: LKML; +Cc: x86, Kees Cook
As of 4.12-rc1 one of my machines triggers the insecure W+X mapping.
It's consistenly 9 entries close to the beginning of the module space,
before the first actual module starts. See below.
Any ideas which avoid bisecting would be appreciated.
Thanks,
tglx
---[ Modules ]---
0xffffffffc0000000-0xffffffffc017d000 1524K pte
0xffffffffc017d000-0xffffffffc017e000 4K RW GLB x pte
0xffffffffc017e000-0xffffffffc017f000 4K pte
0xffffffffc017f000-0xffffffffc0180000 4K RW GLB x pte
0xffffffffc0180000-0xffffffffc0181000 4K pte
0xffffffffc0181000-0xffffffffc0182000 4K RW GLB x pte
0xffffffffc0182000-0xffffffffc0183000 4K pte
0xffffffffc0183000-0xffffffffc0184000 4K RW GLB x pte
0xffffffffc0184000-0xffffffffc0185000 4K pte
0xffffffffc0185000-0xffffffffc0186000 4K RW GLB x pte
0xffffffffc0186000-0xffffffffc0187000 4K pte
0xffffffffc0187000-0xffffffffc0188000 4K RW GLB x pte
0xffffffffc0188000-0xffffffffc0189000 4K pte
0xffffffffc0189000-0xffffffffc018a000 4K RW GLB x pte
0xffffffffc018a000-0xffffffffc018b000 4K pte
0xffffffffc018b000-0xffffffffc018c000 4K RW GLB x pte
0xffffffffc018c000-0xffffffffc018d000 4K pte
0xffffffffc018d000-0xffffffffc018e000 4K RW GLB x pte
First module starts here:
0xffffffffc018e000-0xffffffffc0191000 12K pte
0xffffffffc0191000-0xffffffffc0192000 4K ro GLB x pte
---[ Modules ]---
0xffffffffc0000000-0xffffffffc0200000 2M pmd
0xffffffffc0200000-0xffffffffc02f8000 992K pte
0xffffffffc02f8000-0xffffffffc02f9000 4K RW GLB x pte
0xffffffffc02f9000-0xffffffffc02fa000 4K pte
0xffffffffc02fa000-0xffffffffc02fb000 4K RW GLB x pte
0xffffffffc02fb000-0xffffffffc02fc000 4K pte
0xffffffffc02fc000-0xffffffffc02fd000 4K RW GLB x pte
0xffffffffc02fd000-0xffffffffc02fe000 4K pte
0xffffffffc02fe000-0xffffffffc02ff000 4K RW GLB x pte
0xffffffffc02ff000-0xffffffffc0300000 4K pte
0xffffffffc0300000-0xffffffffc0301000 4K RW GLB x pte
0xffffffffc0301000-0xffffffffc0302000 4K pte
0xffffffffc0302000-0xffffffffc0303000 4K RW GLB x pte
0xffffffffc0303000-0xffffffffc0304000 4K pte
0xffffffffc0304000-0xffffffffc0305000 4K RW GLB x pte
0xffffffffc0305000-0xffffffffc0306000 4K pte
0xffffffffc0306000-0xffffffffc0307000 4K RW GLB x pte
0xffffffffc0307000-0xffffffffc0308000 4K pte
0xffffffffc0308000-0xffffffffc0309000 4K RW GLB x pte
First module starts here:
0xffffffffc0309000-0xffffffffc030c000 12K pte
0xffffffffc030c000-0xffffffffc030d000 4K ro GLB x pte
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [WARNING] x86/mm: Found insecure W+X mapping at address ..
2017-05-23 15:40 [WARNING] x86/mm: Found insecure W+X mapping at address Thomas Gleixner
@ 2017-05-23 15:54 ` Kees Cook
2017-05-23 16:35 ` Thomas Gleixner
0 siblings, 1 reply; 6+ messages in thread
From: Kees Cook @ 2017-05-23 15:54 UTC (permalink / raw)
To: Thomas Gleixner; +Cc: LKML, x86, Masami Hiramatsu, Luis R. Rodriguez
On Tue, May 23, 2017 at 8:40 AM, Thomas Gleixner <tglx@linutronix.de> wrote:
> As of 4.12-rc1 one of my machines triggers the insecure W+X mapping.
>
> It's consistenly 9 entries close to the beginning of the module space,
> before the first actual module starts. See below.
>
> Any ideas which avoid bisecting would be appreciated.
Is this the same as:
https://lkml.org/lkml/2017/5/19/899
?
The location is very similar.
-Kees
>
> Thanks,
>
> tglx
>
> ---[ Modules ]---
> 0xffffffffc0000000-0xffffffffc017d000 1524K pte
> 0xffffffffc017d000-0xffffffffc017e000 4K RW GLB x pte
> 0xffffffffc017e000-0xffffffffc017f000 4K pte
> 0xffffffffc017f000-0xffffffffc0180000 4K RW GLB x pte
> 0xffffffffc0180000-0xffffffffc0181000 4K pte
> 0xffffffffc0181000-0xffffffffc0182000 4K RW GLB x pte
> 0xffffffffc0182000-0xffffffffc0183000 4K pte
> 0xffffffffc0183000-0xffffffffc0184000 4K RW GLB x pte
> 0xffffffffc0184000-0xffffffffc0185000 4K pte
> 0xffffffffc0185000-0xffffffffc0186000 4K RW GLB x pte
> 0xffffffffc0186000-0xffffffffc0187000 4K pte
> 0xffffffffc0187000-0xffffffffc0188000 4K RW GLB x pte
> 0xffffffffc0188000-0xffffffffc0189000 4K pte
> 0xffffffffc0189000-0xffffffffc018a000 4K RW GLB x pte
> 0xffffffffc018a000-0xffffffffc018b000 4K pte
> 0xffffffffc018b000-0xffffffffc018c000 4K RW GLB x pte
> 0xffffffffc018c000-0xffffffffc018d000 4K pte
> 0xffffffffc018d000-0xffffffffc018e000 4K RW GLB x pte
>
> First module starts here:
>
> 0xffffffffc018e000-0xffffffffc0191000 12K pte
> 0xffffffffc0191000-0xffffffffc0192000 4K ro GLB x pte
>
> ---[ Modules ]---
> 0xffffffffc0000000-0xffffffffc0200000 2M pmd
> 0xffffffffc0200000-0xffffffffc02f8000 992K pte
> 0xffffffffc02f8000-0xffffffffc02f9000 4K RW GLB x pte
> 0xffffffffc02f9000-0xffffffffc02fa000 4K pte
> 0xffffffffc02fa000-0xffffffffc02fb000 4K RW GLB x pte
> 0xffffffffc02fb000-0xffffffffc02fc000 4K pte
> 0xffffffffc02fc000-0xffffffffc02fd000 4K RW GLB x pte
> 0xffffffffc02fd000-0xffffffffc02fe000 4K pte
> 0xffffffffc02fe000-0xffffffffc02ff000 4K RW GLB x pte
> 0xffffffffc02ff000-0xffffffffc0300000 4K pte
> 0xffffffffc0300000-0xffffffffc0301000 4K RW GLB x pte
> 0xffffffffc0301000-0xffffffffc0302000 4K pte
> 0xffffffffc0302000-0xffffffffc0303000 4K RW GLB x pte
> 0xffffffffc0303000-0xffffffffc0304000 4K pte
> 0xffffffffc0304000-0xffffffffc0305000 4K RW GLB x pte
> 0xffffffffc0305000-0xffffffffc0306000 4K pte
> 0xffffffffc0306000-0xffffffffc0307000 4K RW GLB x pte
> 0xffffffffc0307000-0xffffffffc0308000 4K pte
> 0xffffffffc0308000-0xffffffffc0309000 4K RW GLB x pte
>
> First module starts here:
>
> 0xffffffffc0309000-0xffffffffc030c000 12K pte
> 0xffffffffc030c000-0xffffffffc030d000 4K ro GLB x pte
--
Kees Cook
Pixel Security
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [WARNING] x86/mm: Found insecure W+X mapping at address ..
2017-05-23 15:54 ` Kees Cook
@ 2017-05-23 16:35 ` Thomas Gleixner
2017-05-23 20:48 ` Thomas Gleixner
0 siblings, 1 reply; 6+ messages in thread
From: Thomas Gleixner @ 2017-05-23 16:35 UTC (permalink / raw)
To: Kees Cook; +Cc: LKML, x86, Masami Hiramatsu, Luis R. Rodriguez
On Tue, 23 May 2017, Kees Cook wrote:
> On Tue, May 23, 2017 at 8:40 AM, Thomas Gleixner <tglx@linutronix.de> wrote:
> > As of 4.12-rc1 one of my machines triggers the insecure W+X mapping.
>
> > It's consistenly 9 entries close to the beginning of the module space,
> > before the first actual module starts. See below.
> >
> > Any ideas which avoid bisecting would be appreciated.
>
> Is this the same as:
>
> https://lkml.org/lkml/2017/5/19/899
>
> ?
>
> The location is very similar.
CONFIG_KPROBES_SANITY_TEST=n does not make it go away, but I suspect it's
something in that area, as I recently switched on all of these self tests.
I'll dig into it later today. Need to walk the dogs first.
Thanks,
tglx
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [WARNING] x86/mm: Found insecure W+X mapping at address ..
2017-05-23 16:35 ` Thomas Gleixner
@ 2017-05-23 20:48 ` Thomas Gleixner
2017-05-23 22:59 ` Steven Rostedt
0 siblings, 1 reply; 6+ messages in thread
From: Thomas Gleixner @ 2017-05-23 20:48 UTC (permalink / raw)
To: Kees Cook
Cc: LKML, x86, Masami Hiramatsu, Luis R. Rodriguez, Steven Rostedt,
Peter Zijlstra
On Tue, 23 May 2017, Thomas Gleixner wrote:
> On Tue, 23 May 2017, Kees Cook wrote:
> > On Tue, May 23, 2017 at 8:40 AM, Thomas Gleixner <tglx@linutronix.de> wrote:
> > > As of 4.12-rc1 one of my machines triggers the insecure W+X mapping.
> >
> > > It's consistenly 9 entries close to the beginning of the module space,
> > > before the first actual module starts. See below.
> > >
> > > Any ideas which avoid bisecting would be appreciated.
> >
> > Is this the same as:
> >
> > https://lkml.org/lkml/2017/5/19/899
> >
> > ?
> >
> > The location is very similar.
>
> CONFIG_KPROBES_SANITY_TEST=n does not make it go away, but I suspect it's
> something in that area, as I recently switched on all of these self tests.
>
> I'll dig into it later today. Need to walk the dogs first.
It's not KPROBES, it's the new fangled ftrace trampoline code. I added a
few printks. All the leaked W+X mappings are allocated via this callchain:
[ 2.620465] module_alloc+0x8e/0xa0
[ 2.620764] ? __fentry__+0x10/0x10
[ 2.621049] arch_ftrace_update_trampoline+0x9f/0x220
[ 2.621453] ? ftrace_caller+0x64/0x64
[ 2.621754] ? __fentry__+0x10/0x10
[ 2.622047] ftrace_startup+0x90/0x200
[ 2.622352] register_ftrace_function+0x50/0x70
[ 2.622725] function_trace_init+0x6d/0xa0
[ 2.623057] trace_selftest_startup_function+0x63/0x4a8
[ 2.623477] run_tracer_selftest+0xfe/0x16c
[ 2.623813] init_trace_selftests+0x5d/0x103
[ 2.624163] ? set_tracepoint_printk+0x3d/0x3d
[ 2.624525] do_one_initcall+0x44/0x170
[ 2.624845] kernel_init_freeable+0x1ff/0x287
[ 2.625199] ? rest_init+0x140/0x140
[ 2.625491] kernel_init+0xe/0x110
[ 2.625775] ret_from_fork+0x2e/0x40
Thanks,
tglx
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [WARNING] x86/mm: Found insecure W+X mapping at address ..
2017-05-23 20:48 ` Thomas Gleixner
@ 2017-05-23 22:59 ` Steven Rostedt
2017-05-24 6:20 ` Thomas Gleixner
0 siblings, 1 reply; 6+ messages in thread
From: Steven Rostedt @ 2017-05-23 22:59 UTC (permalink / raw)
To: Thomas Gleixner
Cc: Kees Cook, LKML, x86, Masami Hiramatsu, Luis R. Rodriguez,
Peter Zijlstra
On Tue, 23 May 2017 22:48:19 +0200 (CEST)
Thomas Gleixner <tglx@linutronix.de> wrote:
> It's not KPROBES, it's the new fangled ftrace trampoline code. I
> added a few printks. All the leaked W+X mappings are allocated via
> this callchain:
The trampoline code isn't new. But it has new users because of the
introduction to synchronize_rcu_tasks(), and there was a bug I fixed in
-rc2 that moved it down because the test was run before
synchronize_rcu_tasks() was functional.
Is this still a bug in rc2?
-- Steve
>
> [ 2.620465] module_alloc+0x8e/0xa0
> [ 2.620764] ? __fentry__+0x10/0x10
> [ 2.621049] arch_ftrace_update_trampoline+0x9f/0x220
> [ 2.621453] ? ftrace_caller+0x64/0x64
> [ 2.621754] ? __fentry__+0x10/0x10
> [ 2.622047] ftrace_startup+0x90/0x200
> [ 2.622352] register_ftrace_function+0x50/0x70
> [ 2.622725] function_trace_init+0x6d/0xa0
> [ 2.623057] trace_selftest_startup_function+0x63/0x4a8
> [ 2.623477] run_tracer_selftest+0xfe/0x16c
> [ 2.623813] init_trace_selftests+0x5d/0x103
> [ 2.624163] ? set_tracepoint_printk+0x3d/0x3d
> [ 2.624525] do_one_initcall+0x44/0x170
> [ 2.624845] kernel_init_freeable+0x1ff/0x287
> [ 2.625199] ? rest_init+0x140/0x140
> [ 2.625491] kernel_init+0xe/0x110
> [ 2.625775] ret_from_fork+0x2e/0x40
>
> Thanks,
>
> tglx
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [WARNING] x86/mm: Found insecure W+X mapping at address ..
2017-05-23 22:59 ` Steven Rostedt
@ 2017-05-24 6:20 ` Thomas Gleixner
0 siblings, 0 replies; 6+ messages in thread
From: Thomas Gleixner @ 2017-05-24 6:20 UTC (permalink / raw)
To: Steven Rostedt
Cc: Kees Cook, LKML, x86, Masami Hiramatsu, Luis R. Rodriguez,
Peter Zijlstra
On Tue, 23 May 2017, Steven Rostedt wrote:
> On Tue, 23 May 2017 22:48:19 +0200 (CEST)
> Thomas Gleixner <tglx@linutronix.de> wrote:
>
>
> > It's not KPROBES, it's the new fangled ftrace trampoline code. I
> > added a few printks. All the leaked W+X mappings are allocated via
> > this callchain:
>
> The trampoline code isn't new. But it has new users because of the
> introduction to synchronize_rcu_tasks(), and there was a bug I fixed in
> -rc2 that moved it down because the test was run before
> synchronize_rcu_tasks() was functional.
>
> Is this still a bug in rc2?
Yes. Otherwise we wouldn't talking about.
Thanks,
tglx
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2017-05-24 6:20 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2017-05-23 15:40 [WARNING] x86/mm: Found insecure W+X mapping at address Thomas Gleixner
2017-05-23 15:54 ` Kees Cook
2017-05-23 16:35 ` Thomas Gleixner
2017-05-23 20:48 ` Thomas Gleixner
2017-05-23 22:59 ` Steven Rostedt
2017-05-24 6:20 ` Thomas Gleixner
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