Any status on timestamp vulnerability fix for 4.X?
Uwe Doering
gemini at geminix.org
Wed Jun 29 21:51:27 GMT 2005
Richard Coleman wrote:
> Uwe Doering wrote:
>
>> Richard Coleman wrote:
>>
>>> Any information on when (or if) the following timestamp vulnerability
>>> will be fixed for 4.X? Any information would be appreciated.
>>>
>>> http://www.kb.cert.org/vuls/id/637934
>>
>> FYI, the fix for RELENG_5 applies to RELENG_4 as is (apart from the
>> CVS version header, of course):
>>
>> http://www.freebsd.org/cgi/cvsweb.cgi/src/sys/netinet/tcp_input.c.diff?r1=1.252.2.15&r2=1.252.2.16&f=u
>>
>> After verifying its semantic correctness for RELENG_4 we've been
>> running the patch for a couple of weeks now with no ill effects.
>>
>> I'm posting this also as an encouragement for committers to go ahead
>> and do the MFC. It's low hanging fruit.
>>
>> Uwe
>
> We tried applying that diff to 4.10, but compilation failed with
>
> tcp_input.o: In function 'tcp_dooptions':
> tcp_input.o(.text+0x21d8): undefined reference to 'TSTMP_GT'
>
> Did you just define that macro? Or was something else required?
Well, this MFC affected two files, actually. I didn't mention it
explicitly because I considered it obvious from the accompanying CVS
comment:
---------------- cut here ----------------
MFC: rev 1.270 of tcp_input.c, rev 1.25 of tcp_seq.h
- Tighten up the Timestamp checks to prevent a spoofed segment from
setting ts_recent to an arbitrary value, stopping further
communication between the two hosts.
- If the Echoed Timestamp is greater than the current time,
fall back to the non RFC 1323 RTT calculation.
---------------- cut here ----------------
So 'tcp_seq.h' needs to be patched, too. Here's the direct link to that
diff:
http://www.freebsd.org/cgi/cvsweb.cgi/src/sys/netinet/tcp_seq.h.diff?r1=1.22.2.1&r2=1.22.2.2&f=u
With both patches in place the kernel ought to compile correctly. Hope
it works for you now.
Uwe
--
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