[tor-bugs] #18089 [Tor]: Tor compiled with --enable-expensive-hardening leads to runtime errors (null pointer passing)

Tue Jan 19 11:59:08 UTC 2016

#18089: Tor compiled with --enable-expensive-hardening leads to runtime errors
(null pointer passing)
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 Reporter:  gk                          |          Owner:
     Type:  defect                      |         Status:  closed
 Priority:  Medium                      |      Milestone:  Tor:
Component:  Tor                         |  0.2.6.x-final
 Severity:  Critical                    |        Version:  Tor: 0.2.3.25
 Keywords:  027-backport, 026-backport  |     Resolution:  fixed
Parent ID:                              |  Actual Points:
  Sponsor:                              |         Points:
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Comment (by teor):

 Replying to [comment:8 bugzilla]:
 > Googling brought this: www.viva64.com/en/b/0178/
 > Did you see it?

 It's from 2012, published on the same day Tor introduced memwipe() to
 address the issues described in that post.

 > On topic: it is not good at all to pass NULL argument to function that
 doesn't expect it.
 > sz=0 is allowed but useless.

 As I said, the impact of this depends on unspecified semantics of those
 functions when passed a NULL pointer. This may vary by C library,
 compiler, and/or platform.

 The patch above fixes these issues, and will be included in the next Tor
 0.2.6 and 0.2.7 releases (and the master branch).

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/18089#comment:9>
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