Review Request 126203: Disable ptrace for kcheckpass and the greeter

[Martin Gräßlin]

> On Nov. 30, 2015, 9:34 a.m., Tobias Berner wrote:
> > I think FreeBSD 10 introduced a similar interface in r277322
> > https://svnweb.freebsd.org/base?view=revision&revision=277322
> > Though it is explicitely stated to not be a "security feature".
> > 
> > According to the man page of progctl 
> > https://www.freebsd.org/cgi/man.cgi?query=procctl&apropos=0&sektion=2&manpath=FreeBSD+10.2-RELEASE&arch=default&format=html
> > this would be PROC_TRACE_CTL with data PROC_TRACE_CTL_DISABLE.
> > 
> > 
> > I will have to ask someone more familiar with that.

> how do I get kwin to output the debug output for the framebuffer backend, with qcdebug lines,

Given the notes on it, that seems fine. It's not my intention to protect against kernel or root.


- Martin


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On Nov. 30, 2015, 9:01 a.m., Martin Gräßlin wrote:
> 
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> This is an automatically generated e-mail. To reply, visit:
> https://git.reviewboard.kde.org/r/126203/
> -----------------------------------------------------------
> 
> (Updated Nov. 30, 2015, 9:01 a.m.)
> 
> 
> Review request for Plasma and Tobias Berner.
> 
> 
> Repository: kscreenlocker
> 
> 
> Description
> -------
> 
> Setting the PR_SET_DUMPABLE flag to 0 for the security relevant
> command kcheckpass and kscreenlocker_greet. If one wants to gdb into
> the running command it will result in:
> 
> ptrace: Operation not permitted.
> 
> For kscreenlocker_greet ptrace is permitted in testing mode.
> 
> As root it's still possible to attach to the process.
> 
> ---
> 
> @Tobias: I assume this is a strong linux-ism. Is there a FreeBSD compareable functionality?
> 
> I'm considering to push this explicitly without an ifdef. It's a new security feature and I want to make non-Linux systems aware of the fact that it adds a new feature and that a replacement should be added.
> 
> 
> Diffs
> -----
> 
>   greeter/main.cpp e4e679e7ef40b319665428281fdba5f4e0b4eb25 
>   kcheckpass/kcheckpass.c fd2d2215bf2199f159a121bb0ce08e7b2b254aaa 
> 
> Diff: https://git.reviewboard.kde.org/r/126203/diff/
> 
> 
> Testing
> -------
> 
> Tried to gdb into the processes: failed
> Tried to gdb into kscreenlocker_greet --testing: succeeded
> Tried to gdb into kscreenlocker_greet as root: succeeded
> 
> 
> Thanks,
> 
> Martin Gräßlin
> 
>

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