[tor-bugs] #33788 [Core Tor/Tor]: Check the return value of tor_inet_ntop() and tor_inet_ntoa() (was: Check the return value of tor_inet_ntop())

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#33788: Check the return value of tor_inet_ntop() and tor_inet_ntoa()
-------------------------------------------------+-------------------------
 Reporter:  teor                                 |          Owner:  (none)
     Type:  defect                               |         Status:  new
 Priority:  Medium                               |      Milestone:  Tor:
                                                 |  0.4.4.x-final
Component:  Core Tor/Tor                         |        Version:
 Severity:  Normal                               |     Resolution:
 Keywords:  044-should, security-low,            |  Actual Points:
  035-backport, 041-backport, 042-backport,      |
  043-backport, outreachy-ipv6, ipv6             |
Parent ID:  #33768                               |         Points:  1
 Reviewer:                                       |        Sponsor:
                                                 |  Sponsor55-must
-------------------------------------------------+-------------------------

Old description:

> The following functions don't check the return value of tor_inet_ntop():
> * tor_dup_ip(), IPv4 only, unlikely to be a serious bug
> * evdns_callback(), multiple times, IPv6, could be serious
>
> These functions should log a bug log using BUG(), and return an error.
>
> We will also need to make their callers check for the error.

New description:

 The following functions don't check the return value of tor_inet_ntop() or
 tor_inet_ntoa():

 IPv6, could be serious:
 * evdns_callback(), multiple times

 IPv4 only, unlikely to be a serious bug:
 * tor_dup_ip()
 * fmt_addr32()
 * evdns_wildcard_check_callback()

 These functions should log a bug log using BUG() or tor_assert_nonfatal(),
 and return an error. (Or for the formatting functions, a sensible
 placeholder string.)

 We will also need to make their callers check for the error.

--

Comment (by teor):

 Also fix tor_inet_ntoa().

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/33788#comment:1>
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