From: Daniel Micay <danielmicay@gmail.com>
To: Linus Torvalds <torvalds@linux-foundation.org>,
"Roberts, William C" <william.c.roberts@intel.com>,
Tejun Heo <tj@kernel.org>
Cc: Jordan Glover <Golden_Miller83@protonmail.ch>,
"Tobin C. Harding" <me@tobin.cc>,
Greg KH <gregkh@linuxfoundation.org>,
Petr Mladek <pmladek@suse.com>, Joe Perches <joe@perches.com>,
Ian Campbell <ijc@hellion.org.uk>,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
"kernel-hardening@lists.openwall.com"
<kernel-hardening@lists.openwall.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will.deacon@arm.com>,
Steven Rostedt <rostedt@goodmis.org>,
Chris Fries <cfries@google.com>,
Dave Weinstein <olorin@google.com>
Subject: Re: [kernel-hardening] [RFC V2 0/6] add more kernel pointer filter options
Date: Wed, 04 Oct 2017 20:29:15 -0400 [thread overview]
Message-ID: <1507163355.1273.63.camel@gmail.com> (raw)
In-Reply-To: <CA+55aFwEZCT6=BCdmaNn5LGeU8g-2qi4OnM9MTOep3NOZVXjMg@mail.gmail.com>
On Wed, 2017-10-04 at 16:52 -0700, Linus Torvalds wrote:
> On Wed, Oct 4, 2017 at 2:58 PM, Roberts, William C
> <william.c.roberts@intel.com> wrote:
> >
> > I agree with you 100% kptr restrict is odd, and I don't think anyone
> > should have had to opt in to be
> > cleansed via kptr_restrict value via %pK. Opt-in never works. One
> > nice thing now, is that checkpatch
> > has checking of %p usages and warns.
>
> Yeah, the checkpatch thing may help for future patches.
>
> > As far as broken things, I can't comment on desktop systems where I
> > think it's harder to make that claim.
> > I see value in embedded systems where I am shipping the whole image,
> > So I know when/what will
> > break.
> >
> > If this was in-tree, Android would be setting this to 4 immediately
> > FWIW.
>
> Does android set it to 2 right now?
Yes, as the universal baseline.
On Google Pixels it's set to this 4 level since August (Android 8.0)
which indicates they plan on moving to that universally.
They only allow dmesg access for core system services so I think their
concern is with formatted strings leaking it elsewhere, not to dmesg.
These are the only services they allow to read dmesg:
private/system_server.te: allow system_server kernel:system syslog_read;
public/dumpstate.te:allow dumpstate kernel:system syslog_read;
public/init.te:allow init kernel:system syslog_read;
public/logd.te:allow logd kernel:system syslog_read;
public/recovery.te: allow recovery kernel:system syslog_read;
logd doesn't read it in production builds, but even when it does in
engineering builds it only gives out access to privileged apps with
READ_LOGS which isn't something a third party app can obtain.
next prev parent reply other threads:[~2017-10-05 0:29 UTC|newest]
Thread overview: 68+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-01 0:06 [kernel-hardening] [RFC V2 0/6] add more kernel pointer filter options Tobin C. Harding
2017-10-01 0:06 ` [kernel-hardening] [RFC V2 1/6] lib: vsprintf: additional kernel pointer filtering options Tobin C. Harding
2017-10-04 8:55 ` Greg KH
2017-10-04 13:08 ` Steven Rostedt
2017-10-04 13:26 ` Greg KH
2017-10-04 13:29 ` Steven Rostedt
2017-10-04 13:54 ` Greg KH
2017-10-01 0:06 ` [kernel-hardening] [RFC V2 2/6] lib: vsprintf: whitelist stack traces Tobin C. Harding
2017-10-02 10:42 ` Will Deacon
2017-10-02 21:49 ` Tobin C. Harding
2017-10-04 8:56 ` Greg KH
2017-10-04 8:58 ` Will Deacon
2017-10-04 9:02 ` Greg KH
2017-10-04 10:42 ` Tobin C. Harding
2017-10-01 0:06 ` [kernel-hardening] [RFC V2 3/6] lib: vsprintf: physical address kernel pointer filtering options Tobin C. Harding
2017-10-04 8:58 ` Greg KH
2017-10-01 0:06 ` [kernel-hardening] [RFC V2 4/6] lib: vsprintf: default kptr_restrict to the maximum value Tobin C. Harding
2017-10-04 8:55 ` Greg KH
2017-10-04 16:42 ` Kees Cook
2017-10-04 16:48 ` Roberts, William C
2017-10-04 17:08 ` Linus Torvalds
2017-10-04 17:28 ` Linus Torvalds
2017-10-04 19:13 ` Jann Horn
2017-10-04 19:23 ` Linus Torvalds
2017-10-01 0:06 ` [kernel-hardening] [RFC V2 5/6] lib: vsprintf: add "%paP", "%papP", and "%padP" specifiers Tobin C. Harding
2017-10-04 8:58 ` Greg KH
2017-10-01 0:06 ` [kernel-hardening] [RFC V2 6/6] drivers: uio: un-restrict sysfs pointers for UIO Tobin C. Harding
2017-10-04 8:58 ` Greg KH
2017-10-01 0:11 ` [kernel-hardening] [RFC V2 0/6] add more kernel pointer filter options Tobin C. Harding
2017-10-04 8:57 ` Greg KH
2017-10-04 10:45 ` Tobin C. Harding
2017-10-04 8:58 ` Greg KH
2017-10-04 10:50 ` Tobin C. Harding
2017-10-04 12:42 ` Greg KH
2017-10-04 13:28 ` Steven Rostedt
2017-10-04 13:31 ` Steven Rostedt
2017-10-04 16:17 ` Roberts, William C
2017-10-04 15:41 ` Linus Torvalds
2017-10-04 16:22 ` Boris Lukashev
2017-10-04 16:29 ` Linus Torvalds
2017-10-04 16:54 ` Steven Rostedt
2017-10-04 18:58 ` Jordan Glover
2017-10-04 19:19 ` Linus Torvalds
2017-10-04 21:58 ` Roberts, William C
2017-10-04 23:21 ` Daniel Micay
2017-10-04 23:52 ` Linus Torvalds
2017-10-05 0:09 ` Linus Torvalds
2017-10-05 13:55 ` Bjorn Helgaas
2017-10-05 0:29 ` Daniel Micay [this message]
2017-10-05 0:35 ` Kees Cook
2017-10-06 8:33 ` Djalal Harouni
2017-10-05 2:19 ` Tobin C. Harding
2017-10-05 3:10 ` Linus Torvalds
2017-10-05 3:15 ` Kees Cook
2017-10-05 15:12 ` Roberts, William C
2017-10-05 16:19 ` Linus Torvalds
2017-10-05 17:10 ` Dave Weinstein
2017-10-07 23:44 ` Theodore Ts'o
2017-10-08 0:08 ` Linus Torvalds
2017-10-13 16:32 ` Roberts, William C
2017-10-13 18:11 ` Linus Torvalds
2017-10-13 19:34 ` Kees Cook
2017-10-13 20:22 ` Linus Torvalds
2017-10-13 20:47 ` Kees Cook
2017-10-13 21:45 ` Linus Torvalds
2017-10-13 22:48 ` Theodore Ts'o
2017-10-13 16:14 ` Roberts, William C
2017-10-04 16:32 ` Ian Campbell
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