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-rw-r--r--hurd/running/debian/dhcp.mdwn97
1 files changed, 96 insertions, 1 deletions
diff --git a/hurd/running/debian/dhcp.mdwn b/hurd/running/debian/dhcp.mdwn
index afa4679..849ff38 100644
--- a/hurd/running/debian/dhcp.mdwn
+++ b/hurd/running/debian/dhcp.mdwn
@@ -1,4 +1,5 @@
-[[!meta copyright="Copyright © 2011, 2012 Free Software Foundation, Inc."]]
+[[!meta copyright="Copyright © 2011, 2012, 2013 Free Software Foundation,
+Inc."]]
[[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable
id="license" text="Permission is granted to copy, distribute and/or modify this
@@ -29,3 +30,97 @@ scripts, but has its own `/libexec/rc` script -- which integrates scripts from
* [[!debbug 616290]]
* [[Proper Hurdy DHCP support|hurd/translator/pfinet/dhcp]]
+
+ * [[!message-id desc="dhclient aborting with a stack smashing error"
+ "874ngfvwn4.fsf@kepler.schwinge.homeip.net"]]
+
+ IRC, freenode, #hurd, 2013-08-21:
+
+ <teythoon> yay, I fixed the path of the dhcp leases file...
+ <teythoon> ... and now dhclient dies of a buffer overflow
+ <teythoon> fortunately the fix is rather simple, anyone who cares about
+ the security of his box just has to stop using isc software
+ <teythoon> the code is full of stuff like char foo[100]; /* surely
+ that's enough */
+ <pinotree> note that our version of isc-dchp (the one in ports) is
+ older than the latest one available in unstable (which is still older
+ than the latest upstream releases)
+ <teythoon> so?
+ <pinotree> dunno, might have been fixed or not
+ <teythoon> ^^ yeah sure
+ <gnu_srs> A lot of software has these limitations and PATH_MAX,
+ MAXPATHLEN issues :(
+ <pinotree> having a limitation is not a problem per-se
+ <teythoon> no, only software written in c has these kind of problems
+ <pinotree> the problem is not checking whether the limits are hit
+ <teythoon> well, looking at the source of isc-dhcp my time is better
+ spent making another dhcp client work on hurd
+ <teythoon> also reading up on bug #616290 does make me want to avoid
+ touching it ever
+ <braunr> hehe
+ <gnu_srs> teythoon: somebody was offering an alternative to the isc
+ dhcpclient, but I think it was rejected by Samuel?
+ <teythoon> why would he do that?
+ <braunr> probably for compliance
+ <gnu_srs> He probably thought they would release a new version soon, is
+ 4.3.0 out yet?
+ <teythoon> well, as soon as my fixes for ifupdown go in, dhclient will
+ start crashing
+ <teythoon> no, there is no new version released
+ <teythoon> no major one that is
+ <teythoon> 4.2.5 is out
+ <gnu_srs> can't you just increase the buffer size, where is the problem
+ exactly?
+ <teythoon> I have no idea
+ <gnu_srs> The Hurd patches are not in 4.2.5, they were promised for
+ 4.3.0a1.
+ <gnu_srs> Still the buffer overflow problem might be present in 4.2.5
+ if patched to build on Hurd.
+ <braunr> there, darnassus now has a fully featured git/gitweb service
+ <teythoon> :)
+ <teythoon> btw, I managed to reproduce the crash reliably
+ <teythoon> rm /var/lib/dhcp/*; dhclient -v /dev/eth0 ... *boom*
+ <teythoon> ditch the -v, everything works, and now that there is a
+ lease file, you can add the -v again and it works
+ <braunr> ew :)
+ <teythoon> and what has dhclient.c to say for its defense?
+ <teythoon> log_info("%s", "");
+ <teythoon> hm, not much :/
+
+ IRC, freenode, #hurd, 2013-08-22:
+
+ <teythoon> uh, the isc-dhcp situation is a huge pita, the source on
+ -ports does not compile anymore :/
+
+ IRC, freenode, #hurd, 2013-08-23:
+
+ <gnu_srs> teythoon: Was it the slash in the network interface names
+ that caused the buffer overflow in dhclient?
+ <teythoon> gnu_srs: no, previously no dhcp leases file was written and
+ everything was fine
+ <pinotree> teythoon: did you really develop your patch against that old
+ version of ifupdown?
+ <teythoon> gnu_srs: now it is written, and for some reason dhclient
+ crashes *iff* -v is given *and* there is no previous lease file
+ <teythoon> pinotree: no, I did not. that was only reportbug including
+ information from my desktop machine without asking me
+ <teythoon> but when I first looked at ifupdown it was still a 6000
+ lines noweb file >,<
+ <teythoon> that was fun
+ <pinotree> which version is it against?
+ <teythoon> hg tip
+
+ IRC, freenode, #hurd, 2013-08-30:
+
+ <tschwinge> teythoon: I understand correctly that you found that
+ id:"874ngfvwn4.fsf@kepler.schwinge.homeip.net" in fact was really
+ "just" a buffer overflow in the dhclient code?
+ <teythoon> tschwinge: ah, most interesting, I didn't realize that you
+ stumbled across this as well
+ <teythoon> to be honest I don't know what's going on there, I only
+ observed what I wrote in my report
+ <teythoon> for me it started crashing once the lease file was actually
+ a valid path (i.e. not to a non-existing directory b/c of the slashes
+ in /dev/eth0)
+ <teythoon> I tried to rebuild the package served on debian-ports, but
+ that failed