Re: [tor-bugs] #22926 [Core Tor/Tor]: The Tor compression code can call functions that are NULL

[Tor Bug Tracker & Wiki]

#22926: The Tor compression code can call functions that are NULL
-+
 Reporter:  teor |  Owner:  ahf
 Type:  defect   | Status:  needs_revision
 Priority:  Medium   |  Milestone:  Tor: 0.3.3.x-final
Component:  Core Tor/Tor |Version:  Tor: 0.3.1.1-alpha
 Severity:  Normal   | Resolution:
 Keywords:  review-group-32  |  Actual Points:
Parent ID:   | Points:  1
 Reviewer:  mikeperry|Sponsor:
-+

Comment (by teor):

 There's a lot of detail here, and I don't have time to check it all on my
 Mac.

 The original bug report was from the shadow author, who now wants to
 integrate building the tor shadow plugin into configure.ac.

--
Ticket URL: 
Tor Bug Tracker & Wiki 
The Tor Project: anonymity online
___
tor-bugs mailing list
tor-bugs@lists.torproject.org
https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-bugs

Re: [tor-bugs] #22926 [Core Tor/Tor]: The Tor compression code can call functions that are NULL

[Tor Bug Tracker & Wiki]

#22926: The Tor compression code can call functions that are NULL
-+
 Reporter:  teor |  Owner:  ahf
 Type:  defect   | Status:  needs_revision
 Priority:  Medium   |  Milestone:  Tor: 0.3.3.x-final
Component:  Core Tor/Tor |Version:  Tor: 0.3.1.1-alpha
 Severity:  Normal   | Resolution:
 Keywords:  review-group-32  |  Actual Points:
Parent ID:   | Points:  1
 Reviewer:  mikeperry|Sponsor:
-+

Comment (by Hello71):

 Replying to [comment:25 teor]:
 > shadow's tor plugin will fail this test, as will many platforms that use
 tor as a library.

 did you test this? if so, what steps exactly did you use? as far as I can
 tell, shadow-plugin-tor:

 1. does not use weak linking at all
 2. does not actually build the plugin using autotools, so almost any
 "funny business" that the plugin build process could do would not be
 detected by any configure.ac checks anyways.

 however, after extensive research, I have found that apparently on Mac,
 the linker (whose official man page is not even available online!) allows
 you to shoot your whole limb off at the same time using the poorly-
 engineered `-weak_reference_mismatches` and `-weak-l` options. as pointed
 out in the man page, these options are poorly designed because it silently
 alters the behavior of unrelated program code. these options are in fact
 so poorly conceived that Googling for "weak_reference_mismatches" returns
 almost entirely results saying to turn it off.

 however! even if this option is passed, I am still convinced that the
 configure check will be almost entirely ineffective for three reasons.

 1. assuming the library is installed correctly, even if the user has
 enabled the limb-gun option, this configure check will pass just fine, and
 even the build products will function correctly. only if the user
 subsequently *uninstalls* the library, tor will suddenly start crashing.
 (and again, only if you used the limb-gun option.)
 2. if the library provides only a subset of the necessary symbols, tor
 will compile but fail to run. unfortunately, the configure check still
 doesn't help, because it only checks that the version function works
 (which is the only function sorta guaranteed not to ever change, the
 opposite of the requirement here), not that all the functions work.
 3. as far as I know, autotools does not support magically configuring an
 executable to be compiled as a shared library instead. this is why shadow-
 plugin-tor doesn't bother and builds tor with cmake instead. this
 configure check will obviously not work if it is not called.

--
Ticket URL: 
Tor Bug Tracker & Wiki 
The Tor Project: anonymity online
___
tor-bugs mailing list
tor-bugs@lists.torproject.org
https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-bugs

Re: [tor-bugs] #22926 [Core Tor/Tor]: The Tor compression code can call functions that are NULL

[Tor Bug Tracker & Wiki]

#22926: The Tor compression code can call functions that are NULL
-+
 Reporter:  teor |  Owner:  ahf
 Type:  defect   | Status:  needs_revision
 Priority:  Medium   |  Milestone:  Tor: 0.3.3.x-final
Component:  Core Tor/Tor |Version:  Tor: 0.3.1.1-alpha
 Severity:  Normal   | Resolution:
 Keywords:  review-group-32  |  Actual Points:
Parent ID:   | Points:  1
 Reviewer:  mikeperry|Sponsor:
-+

Comment (by teor):

 shadow's tor plugin will fail this test, as will many platforms that use
 tor as a library.

--
Ticket URL: 
Tor Bug Tracker & Wiki 
The Tor Project: anonymity online
___
tor-bugs mailing list
tor-bugs@lists.torproject.org
https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-bugs

Re: [tor-bugs] #22926 [Core Tor/Tor]: The Tor compression code can call functions that are NULL

[Tor Bug Tracker & Wiki]

#22926: The Tor compression code can call functions that are NULL
-+
 Reporter:  teor |  Owner:  ahf
 Type:  defect   | Status:  needs_revision
 Priority:  Medium   |  Milestone:  Tor: 0.3.3.x-final
Component:  Core Tor/Tor |Version:  Tor: 0.3.1.1-alpha
 Severity:  Normal   | Resolution:
 Keywords:  review-group-32  |  Actual Points:
Parent ID:   | Points:  1
 Reviewer:  mikeperry|Sponsor:
-+

Comment (by mikeperry):

 Oh, also did we find a platform to test such that this test fails when
 weak/lazy binding is in effect?

--
Ticket URL: 
Tor Bug Tracker & Wiki 
The Tor Project: anonymity online
___
tor-bugs mailing list
tor-bugs@lists.torproject.org
https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-bugs

Re: [tor-bugs] #22926 [Core Tor/Tor]: The Tor compression code can call functions that are NULL

[Tor Bug Tracker & Wiki]

#22926: The Tor compression code can call functions that are NULL
-+
 Reporter:  teor |  Owner:  ahf
 Type:  defect   | Status:  needs_revision
 Priority:  Medium   |  Milestone:  Tor: 0.3.3.x-final
Component:  Core Tor/Tor |Version:  Tor: 0.3.1.1-alpha
 Severity:  Normal   | Resolution:
 Keywords:  review-group-32  |  Actual Points:
Parent ID:   | Points:  1
 Reviewer:  mikeperry|Sponsor:
-+
Changes (by mikeperry):

 * status:  needs_review => needs_revision


Comment:

 It has been a while since I have done autoconf, but as far as that goes,
 this looks good - has a sane default for cross compile given the situation
 (assume it works).

 As to the larger question, I can see an argument for just going this check
 for one library to check if lazy linking is enabled globally. But there
 probably should be a comment in the autoconf test to say that's what we're
 doing (and why we are only testing this with one library). Marking
 needs_revision for that.

 Also make check-changes fails because of the # in the bug line.

--
Ticket URL: 
Tor Bug Tracker & Wiki 
The Tor Project: anonymity online
___
tor-bugs mailing list
tor-bugs@lists.torproject.org
https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-bugs

Re: [tor-bugs] #22926 [Core Tor/Tor]: The Tor compression code can call functions that are NULL

[Tor Bug Tracker & Wiki]

#22926: The Tor compression code can call functions that are NULL
-+
 Reporter:  teor |  Owner:  ahf
 Type:  defect   | Status:  needs_review
 Priority:  Medium   |  Milestone:  Tor: 0.3.3.x-final
Component:  Core Tor/Tor |Version:  Tor: 0.3.1.1-alpha
 Severity:  Normal   | Resolution:
 Keywords:  review-group-32  |  Actual Points:
Parent ID:   | Points:  1
 Reviewer:  mikeperry|Sponsor:
-+
Changes (by mikeperry):

 * reviewer:   => mikeperry


--
Ticket URL: 
Tor Bug Tracker & Wiki 
The Tor Project: anonymity online
___
tor-bugs mailing list
tor-bugs@lists.torproject.org
https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-bugs

Re: [tor-bugs] #22926 [Core Tor/Tor]: The Tor compression code can call functions that are NULL

[Tor Bug Tracker & Wiki]

#22926: The Tor compression code can call functions that are NULL
--+
 Reporter:  teor  |  Owner:  ahf
 Type:  defect| Status:  needs_review
 Priority:  Medium|  Milestone:  Tor: 0.3.3.x-final
Component:  Core Tor/Tor  |Version:  Tor: 0.3.1.1-alpha
 Severity:  Normal| Resolution:
 Keywords:|  Actual Points:
Parent ID:| Points:  1
 Reviewer:|Sponsor:
--+

Comment (by ahf):

 Potential patch in https://oniongit.eu/ahf/tor/merge_requests/6

--
Ticket URL: 
Tor Bug Tracker & Wiki 
The Tor Project: anonymity online
___
tor-bugs mailing list
tor-bugs@lists.torproject.org
https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-bugs

Re: [tor-bugs] #22926 [Core Tor/Tor]: The Tor compression code can call functions that are NULL

[Tor Bug Tracker & Wiki]

#22926: The Tor compression code can call functions that are NULL
--+
 Reporter:  teor  |  Owner:  ahf
 Type:  defect| Status:  needs_review
 Priority:  Medium|  Milestone:  Tor: 0.3.3.x-final
Component:  Core Tor/Tor  |Version:  Tor: 0.3.1.1-alpha
 Severity:  Normal| Resolution:
 Keywords:|  Actual Points:
Parent ID:| Points:  1
 Reviewer:|Sponsor:
--+

Comment (by Hello71):

 (my point is that if you start fiddling with .c files, you get to play 52
 pickup on your own.)

--
Ticket URL: 
Tor Bug Tracker & Wiki 
The Tor Project: anonymity online
___
tor-bugs mailing list
tor-bugs@lists.torproject.org
https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-bugs

Re: [tor-bugs] #22926 [Core Tor/Tor]: The Tor compression code can call functions that are NULL

[Tor Bug Tracker & Wiki]

#22926: The Tor compression code can call functions that are NULL
--+
 Reporter:  teor  |  Owner:  ahf
 Type:  defect| Status:  needs_review
 Priority:  Medium|  Milestone:  Tor: 0.3.3.x-final
Component:  Core Tor/Tor  |Version:  Tor: 0.3.1.1-alpha
 Severity:  Normal| Resolution:
 Keywords:|  Actual Points:
Parent ID:| Points:  1
 Reviewer:|Sponsor:
--+
Changes (by Hello71):

 * cc: alex_y_xu@… (added)


Comment:

 also, the following also fails to compile (on x86-64 Linux):

 a.c:
 {{{
 void a() __attribute__((weak));
 void b();

 int main() {
 a();
 b();
 return 0;
 }
 }}}

 b.c:

 {{{
 void a();

 void b() {
 a();
 }
 }}}

--
Ticket URL: 
Tor Bug Tracker & Wiki 
The Tor Project: anonymity online
___
tor-bugs mailing list
tor-bugs@lists.torproject.org
https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-bugs

Re: [tor-bugs] #22926 [Core Tor/Tor]: The Tor compression code can call functions that are NULL

[Tor Bug Tracker & Wiki]

#22926: The Tor compression code can call functions that are NULL
--+
 Reporter:  teor  |  Owner:  ahf
 Type:  defect| Status:  needs_review
 Priority:  Medium|  Milestone:  Tor: 0.3.3.x-final
Component:  Core Tor/Tor  |Version:  Tor: 0.3.1.1-alpha
 Severity:  Normal| Resolution:
 Keywords:|  Actual Points:
Parent ID:| Points:  1
 Reviewer:|Sponsor:
--+

Comment (by Hello71):

 how exactly does one "enable weak symbols"? as far as I can tell, on both
 Mac and Linux, this process involves inserting `__attribute__((weak))` or
 `#pragma weak` in the actual source files that reference the symbol in
 question. even in cases of shared libraries, AIUI, if executable `a` NEEDS
 library `b.so`, and `a` has a weak symbol `f` with no default, and `b.so`
 has an undefined symbol `f`, then `a` will fail to start.

--
Ticket URL: 
Tor Bug Tracker & Wiki 
The Tor Project: anonymity online
___
tor-bugs mailing list
tor-bugs@lists.torproject.org
https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-bugs

Re: [tor-bugs] #22926 [Core Tor/Tor]: The Tor compression code can call functions that are NULL

[Tor Bug Tracker & Wiki]

#22926: The Tor compression code can call functions that are NULL
--+
 Reporter:  teor  |  Owner:  ahf
 Type:  defect| Status:  needs_review
 Priority:  Medium|  Milestone:  Tor: 0.3.3.x-final
Component:  Core Tor/Tor  |Version:  Tor: 0.3.1.1-alpha
 Severity:  Normal| Resolution:
 Keywords:|  Actual Points:
Parent ID:| Points:  1
 Reviewer:|Sponsor:
--+

Comment (by teor):

 I think Nick is right, checking for NULL functions could rapidly get out
 of control.
 (I don't think we should check for mandatory libraries. But then I asked
 myself: why bother to check at all?)

 I suggest we check that the zstd and lzma library functions are non-NULL
 at configure time. And fail if they are NULL.
 That way, builders get instant feedback if their linker flags or install
 are broken.

 People who design custom build processes will have to make sure they work
 themselves.

--
Ticket URL: 
Tor Bug Tracker & Wiki 
The Tor Project: anonymity online
___
tor-bugs mailing list
tor-bugs@lists.torproject.org
https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-bugs

Re: [tor-bugs] #22926 [Core Tor/Tor]: The Tor compression code can call functions that are NULL

[Tor Bug Tracker & Wiki]

#22926: The Tor compression code can call functions that are NULL
--+
 Reporter:  teor  |  Owner:  ahf
 Type:  defect| Status:  needs_review
 Priority:  Medium|  Milestone:  Tor: 0.3.3.x-final
Component:  Core Tor/Tor  |Version:  Tor: 0.3.1.1-alpha
 Severity:  Normal| Resolution:
 Keywords:|  Actual Points:
Parent ID:| Points:  1
 Reviewer:|Sponsor:
--+

Comment (by ahf):

 I'm conflicted about this.

 I don't think doing this is a particularly good solution. I added the
 changes to the zlib code in case we move away from Tor's
 `TOR_SEARCH_LIBRARY()` where this issue isn't detected.

 The other option is that we add the `configure` checks that
 `TOR_SEARCH_LIBRARY()` adds to `configure` to ensure that our zstd/lzma
 code works in the same way.

 This is of course still an issue for OpenSSL, Libevent, and other external
 dependencies we may have.

 Would you prefer a `configure` check to this or should we do something
 entirely different?

--
Ticket URL: 
Tor Bug Tracker & Wiki 
The Tor Project: anonymity online
___
tor-bugs mailing list
tor-bugs@lists.torproject.org
https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-bugs

Re: [tor-bugs] #22926 [Core Tor/Tor]: The Tor compression code can call functions that are NULL

[Tor Bug Tracker & Wiki]

#22926: The Tor compression code can call functions that are NULL
--+
 Reporter:  teor  |  Owner:  ahf
 Type:  defect| Status:  needs_review
 Priority:  Medium|  Milestone:  Tor: 0.3.3.x-final
Component:  Core Tor/Tor  |Version:  Tor: 0.3.1.1-alpha
 Severity:  Normal| Resolution:
 Keywords:|  Actual Points:
Parent ID:| Points:  1
 Reviewer:|Sponsor:
--+

Comment (by nickm):

 Looks okay at first glance, but: do we really want to go down this road?
 Will we wind up doing this for every shared library we use in Tor,
 including libevent and openssl?

 Also, zlib is mandatory: we can't keep going if zlib isn't going to work.

--
Ticket URL: 
Tor Bug Tracker & Wiki 
The Tor Project: anonymity online
___
tor-bugs mailing list
tor-bugs@lists.torproject.org
https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-bugs

Re: [tor-bugs] #22926 [Core Tor/Tor]: The Tor compression code can call functions that are NULL

[Tor Bug Tracker & Wiki]

#22926: The Tor compression code can call functions that are NULL
--+
 Reporter:  teor  |  Owner:  ahf
 Type:  defect| Status:  needs_review
 Priority:  Medium|  Milestone:  Tor: 0.3.3.x-final
Component:  Core Tor/Tor  |Version:  Tor: 0.3.1.1-alpha
 Severity:  Normal| Resolution:
 Keywords:|  Actual Points:
Parent ID:| Points:  1
 Reviewer:|Sponsor:
--+

Comment (by ahf):

 One thing to keep in mind, I'm not fully sure the patch I've proposed work
 under the given condition. I assume that doing `` yields `NULL`
 if the function is unavailable.

--
Ticket URL: 
Tor Bug Tracker & Wiki 
The Tor Project: anonymity online
___
tor-bugs mailing list
tor-bugs@lists.torproject.org
https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-bugs

Re: [tor-bugs] #22926 [Core Tor/Tor]: The Tor compression code can call functions that are NULL

[Tor Bug Tracker & Wiki]

#22926: The Tor compression code can call functions that are NULL
--+
 Reporter:  teor  |  Owner:  ahf
 Type:  defect| Status:  needs_review
 Priority:  Medium|  Milestone:  Tor: 0.3.3.x-final
Component:  Core Tor/Tor  |Version:  Tor: 0.3.1.1-alpha
 Severity:  Normal| Resolution:
 Keywords:|  Actual Points:
Parent ID:| Points:  1
 Reviewer:|Sponsor:
--+

Comment (by teor):

 Maybe we don't need to check at configure time?
 I think a warning is enough.

 The documentation could form part of the tor_api header or docs.

--
Ticket URL: 
Tor Bug Tracker & Wiki 
The Tor Project: anonymity online
___
tor-bugs mailing list
tor-bugs@lists.torproject.org
https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-bugs

Re: [tor-bugs] #22926 [Core Tor/Tor]: The Tor compression code can call functions that are NULL

[Tor Bug Tracker & Wiki]

#22926: The Tor compression code can call functions that are NULL
--+
 Reporter:  teor  |  Owner:  ahf
 Type:  defect| Status:  needs_review
 Priority:  Medium|  Milestone:  Tor: 0.3.3.x-final
Component:  Core Tor/Tor  |Version:  Tor: 0.3.1.1-alpha
 Severity:  Normal| Resolution:
 Keywords:|  Actual Points:
Parent ID:| Points:  1
 Reviewer:|Sponsor:
--+
Changes (by ahf):

 * status:  assigned => needs_review


Comment:

 There's a potential patch for parts of this issue in
 https://gitlab.com/ahf/tor/merge_requests/22

 Note that the patch does the `NULL` function checks for the zlib backend:
 we might want to consider adding a `tor_assert(0)` in the pathological
 case there since zlib is still required to be able to use Tor.

 I'm marking this `needs_review`, but these patches does not fix everything
 Teor mentioned above. We still need to add checks to `configure` and
 document the weak linking issue.

--
Ticket URL: 
Tor Bug Tracker & Wiki 
The Tor Project: anonymity online
___
tor-bugs mailing list
tor-bugs@lists.torproject.org
https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-bugs

Re: [tor-bugs] #22926 [Core Tor/Tor]: The Tor compression code can call functions that are NULL

[Tor Bug Tracker & Wiki]

#22926: The Tor compression code can call functions that are NULL
--+
 Reporter:  teor  |  Owner:  ahf
 Type:  defect| Status:  assigned
 Priority:  Medium|  Milestone:  Tor: 0.3.3.x-final
Component:  Core Tor/Tor  |Version:  Tor: 0.3.1.1-alpha
 Severity:  Normal| Resolution:
 Keywords:|  Actual Points:
Parent ID:| Points:  1
 Reviewer:|Sponsor:
--+

Comment (by teor):

 Replying to [comment:9 nickm]:
 > Have we advanced our thinking any here?  It still seems to me that
 "don't do that then" is the right solution.

 We have decided to support running Tor as a library.
 Therefore, we will see more linking issues in future.

 I suggest we:
 * document this weak linking issue
 * check for NULL pointers to functions in optional libraries at configure
 time
 * check for NULL pointers to functions in optional libraries at runtime

 Otherwise, people will be surprised the first time their tor tries to use
 the compression code.

--
Ticket URL: 
Tor Bug Tracker & Wiki 
The Tor Project: anonymity online
___
tor-bugs mailing list
tor-bugs@lists.torproject.org
https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-bugs

Re: [tor-bugs] #22926 [Core Tor/Tor]: The Tor compression code can call functions that are NULL

[Tor Bug Tracker & Wiki]

#22926: The Tor compression code can call functions that are NULL
--+
 Reporter:  teor  |  Owner:  ahf
 Type:  defect| Status:  assigned
 Priority:  Medium|  Milestone:  Tor: 0.3.3.x-final
Component:  Core Tor/Tor  |Version:  Tor: 0.3.1.1-alpha
 Severity:  Normal| Resolution:
 Keywords:|  Actual Points:
Parent ID:| Points:  1
 Reviewer:|Sponsor:
--+

Comment (by nickm):

 Have we advanced our thinking any here?  It still seems to me that "don't
 do that then" is the right solution.

--
Ticket URL: 
Tor Bug Tracker & Wiki 
The Tor Project: anonymity online
___
tor-bugs mailing list
tor-bugs@lists.torproject.org
https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-bugs

Re: [tor-bugs] #22926 [Core Tor/Tor]: The Tor compression code can call functions that are NULL

[Tor Bug Tracker & Wiki]

#22926: The Tor compression code can call functions that are NULL
--+
 Reporter:  teor  |  Owner:  ahf
 Type:  defect| Status:  assigned
 Priority:  Medium|  Milestone:  Tor: 0.3.3.x-final
Component:  Core Tor/Tor  |Version:  Tor: 0.3.1.1-alpha
 Severity:  Normal| Resolution:
 Keywords:|  Actual Points:
Parent ID:| Points:  1
 Reviewer:|Sponsor:
--+

Comment (by mtigas):

 Replying to [comment:7 ahf]:
 > You mentioned during the mobile session in Montreal that you were going
 to look into adding support for LZMA and Zstandard for OnionBrowser.
 >
 > Do you think this is going to be an issue for you on iOS?

 Actually, my current guess is that this isn't an issue for iOS at all
 because the dependencies (including tor) get built as static libraries and
 then they're all linked into the app's single executable anyway.

 I'm hoping to take a stab at building with liblzma (in Tor.framework /
 Onion Browser) over the next week or so. So maybe I'll have more specific
 feedback for y'all soon.

--
Ticket URL: 
Tor Bug Tracker & Wiki 
The Tor Project: anonymity online
___
tor-bugs mailing list
tor-bugs@lists.torproject.org
https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-bugs

Re: [tor-bugs] #22926 [Core Tor/Tor]: The Tor compression code can call functions that are NULL

[Tor Bug Tracker & Wiki]

#22926: The Tor compression code can call functions that are NULL
--+
 Reporter:  teor  |  Owner:  ahf
 Type:  defect| Status:  assigned
 Priority:  Medium|  Milestone:  Tor: 0.3.3.x-final
Component:  Core Tor/Tor  |Version:  Tor: 0.3.1.1-alpha
 Severity:  Normal| Resolution:
 Keywords:|  Actual Points:
Parent ID:| Points:  1
 Reviewer:|Sponsor:
--+
Changes (by ahf):

 * cc: mtigas (added)


Comment:

 Hey Mike,

 You mentioned during the mobile session in Montreal that you were going to
 look into adding support for LZMA and Zstandard for OnionBrowser.

 Do you think this is going to be an issue for you on iOS?

--
Ticket URL: 
Tor Bug Tracker & Wiki 
The Tor Project: anonymity online
___
tor-bugs mailing list
tor-bugs@lists.torproject.org
https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-bugs

Re: [tor-bugs] #22926 [Core Tor/Tor]: The Tor compression code can call functions that are NULL

[Tor Bug Tracker & Wiki]

#22926: The Tor compression code can call functions that are NULL
--+
 Reporter:  teor  |  Owner:  ahf
 Type:  defect| Status:  assigned
 Priority:  Medium|  Milestone:  Tor: 0.3.3.x-final
Component:  Core Tor/Tor  |Version:  Tor: 0.3.1.1-alpha
 Severity:  Normal| Resolution:
 Keywords:|  Actual Points:
Parent ID:| Points:  1
 Reviewer:|Sponsor:
--+
Changes (by nickm):

 * milestone:  Tor: 0.3.1.x-final => Tor: 0.3.3.x-final


--
Ticket URL: 
Tor Bug Tracker & Wiki 
The Tor Project: anonymity online
___
tor-bugs mailing list
tor-bugs@lists.torproject.org
https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-bugs

Re: [tor-bugs] #22926 [Core Tor/Tor]: The Tor compression code can call functions that are NULL

[Tor Bug Tracker & Wiki]

#22926: The Tor compression code can call functions that are NULL
--+
 Reporter:  teor  |  Owner:  ahf
 Type:  defect| Status:  assigned
 Priority:  Medium|  Milestone:  Tor: 0.3.1.x-final
Component:  Core Tor/Tor  |Version:  Tor: 0.3.1.1-alpha
 Severity:  Normal| Resolution:
 Keywords:|  Actual Points:
Parent ID:| Points:  1
 Reviewer:|Sponsor:
--+

Comment (by teor):

 Replying to [comment:4 nickm]:
 > If this is a hard issue to fix, we might just say "don't do that then"
 -- we don't build Tor with weak/lazy symbol binding ourselves, and while
 we don't tell people not to do it, we could just say that it is incumbent
 on people who change our build system to keep it working with their
 changes.
 >
 > Thoughts?

 Documenting this issue seems like a sensible solution, but we should check
 if this affects iOS and Tor.framework before deciding. If it does affect
 iOS, and we want to support iOS as a first-class platform, maybe linking
 would be a good check to add.

 I'd also phrase it as "pass unusual [linker] options to our build system",
 as "change our build system" could be unclear.

--
Ticket URL: 
Tor Bug Tracker & Wiki 
The Tor Project: anonymity online
___
tor-bugs mailing list
tor-bugs@lists.torproject.org
https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-bugs

Re: [tor-bugs] #22926 [Core Tor/Tor]: The Tor compression code can call functions that are NULL

[Tor Bug Tracker & Wiki]

#22926: The Tor compression code can call functions that are NULL
--+
 Reporter:  teor  |  Owner:  ahf
 Type:  defect| Status:  assigned
 Priority:  Medium|  Milestone:  Tor: 0.3.1.x-final
Component:  Core Tor/Tor  |Version:  Tor: 0.3.1.1-alpha
 Severity:  Normal| Resolution:
 Keywords:|  Actual Points:
Parent ID:| Points:  1
 Reviewer:|Sponsor:
--+

Comment (by nickm):

 If this is a hard issue to fix, we might just say "don't do that then" --
 we don't build Tor with weak/lazy symbol binding ourselves, and while we
 don't tell people not to do it, we could just say that it is incumbent on
 people who change our build system to keep it working with their changes.

 Thoughts?

--
Ticket URL: 
Tor Bug Tracker & Wiki 
The Tor Project: anonymity online
___
tor-bugs mailing list
tor-bugs@lists.torproject.org
https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-bugs

Re: [tor-bugs] #22926 [Core Tor/Tor]: The Tor compression code can call functions that are NULL

[Tor Bug Tracker & Wiki]

#22926: The Tor compression code can call functions that are NULL
--+
 Reporter:  teor  |  Owner:  ahf
 Type:  defect| Status:  assigned
 Priority:  Medium|  Milestone:  Tor: 0.3.1.x-final
Component:  Core Tor/Tor  |Version:  Tor: 0.3.1.1-alpha
 Severity:  Normal| Resolution:
 Keywords:|  Actual Points:
Parent ID:| Points:  1
 Reviewer:|Sponsor:
--+

Comment (by ahf):

 This is going to be an issue for all external dependencies that we use via
 pkg-config I think. The old `TOR_SEARCH_LIBRARY()` macro is probably
 unaffected since it tries to build a small test file.

 I will try to do the same as we do in `TOR_SEARCH_LIBRARY()` when the
 library is found to ensure that we can link against the .so and that the
 headers are present.

--
Ticket URL: 
Tor Bug Tracker & Wiki 
The Tor Project: anonymity online
___
tor-bugs mailing list
tor-bugs@lists.torproject.org
https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-bugs

Re: [tor-bugs] #22926 [Core Tor/Tor]: The Tor compression code can call functions that are NULL

[Tor Bug Tracker & Wiki]

#22926: The Tor compression code can call functions that are NULL
--+
 Reporter:  teor  |  Owner:  ahf
 Type:  defect| Status:  assigned
 Priority:  Medium|  Milestone:  Tor: 0.3.1.x-final
Component:  Core Tor/Tor  |Version:  Tor: 0.3.1.1-alpha
 Severity:  Normal| Resolution:
 Keywords:|  Actual Points:
Parent ID:| Points:  1
 Reviewer:|Sponsor:
--+

Comment (by teor):

 Can we make configure check that linking results in non-NULL symbols, as
 well as checking that the headers are present?

--
Ticket URL: 
Tor Bug Tracker & Wiki 
The Tor Project: anonymity online
___
tor-bugs mailing list
tor-bugs@lists.torproject.org
https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-bugs

Re: [tor-bugs] #22926 [Core Tor/Tor]: The Tor compression code can call functions that are NULL

[Tor Bug Tracker & Wiki]

#22926: The Tor compression code can call functions that are NULL
--+
 Reporter:  teor  |  Owner:  ahf
 Type:  defect| Status:  assigned
 Priority:  Medium|  Milestone:  Tor: 0.3.1.x-final
Component:  Core Tor/Tor  |Version:  Tor: 0.3.1.1-alpha
 Severity:  Normal| Resolution:
 Keywords:|  Actual Points:
Parent ID:| Points:  1
 Reviewer:|Sponsor:
--+
Changes (by nickm):

 * owner:   => ahf
 * status:  new => assigned


--
Ticket URL: 
Tor Bug Tracker & Wiki 
The Tor Project: anonymity online
___
tor-bugs mailing list
tor-bugs@lists.torproject.org
https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-bugs

[tor-bugs] #22926 [Core Tor/Tor]: The Tor compression code can call functions that are NULL

[Tor Bug Tracker & Wiki]

#22926: The Tor compression code can call functions that are NULL
--+
 Reporter:  teor  |  Owner:
 Type:  defect| Status:  new
 Priority:  Medium|  Milestone:  Tor: 0.3.1.x-final
Component:  Core Tor/Tor  |Version:  Tor: 0.3.1.1-alpha
 Severity:  Normal|   Keywords:
Actual Points:|  Parent ID:
   Points:  1 |   Reviewer:
  Sponsor:|
--+
 The new Tor compression code in 0.3.1 assumes that all the compression
 functions are bound at runtime.

 For example, tor_lzma_method_supported() returns 1 when HAVE_LZMA is
 defined, but that doesn't mean that lzma_version_string() has actually
 been bound to a non-NULL address in the binary.

 This is more likely to happens when tor is used as a shared library rather
 than linked as an executable (shadow, iOS), and when using weak, lazy
 symbol binding.

 This might not be an issue we can solve unless we check for all the
 symbols being NULL at runtime. Maybe the responsibility for proper linking
 is on people who are compiling tor with weak, lazy symbol binding.

 This bug was discovered by Rob Jansen when running shadow.

--
Ticket URL: 
Tor Bug Tracker & Wiki 
The Tor Project: anonymity online
___
tor-bugs mailing list
tor-bugs@lists.torproject.org
https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-bugs