[tor-bugs] #30920 [Core Tor/Tor]: Detect uint64 overflow in config_parse_units()

[Tor Bug Tracker & Wiki]

#30920: Detect uint64 overflow in config_parse_units()
---------------------------+------------------------------------
 Reporter:  nickm          |          Owner:  (none)
     Type:  defect         |         Status:  needs_revision
 Priority:  Low            |      Milestone:  Tor: 0.4.3.x-final
Component:  Core Tor/Tor   |        Version:
 Severity:  Minor          |     Resolution:
 Keywords:  easy overflow  |  Actual Points:
Parent ID:                 |         Points:
 Reviewer:  teor           |        Sponsor:
---------------------------+------------------------------------

Comment (by guigom):

 Hi Teor.

 I've updated the PR with a couple of tests, one that fails the double
 check and one that passes double but fails int check.

 Reasoning:

 // Fails double check //
 15000000.5 TB fails double check as its a greater floating number than
 (double)INT64_MAX

 // Passes double check but fails int check //
 8388608.1 TB passes double check because it falls in the same value as
 (double)INT64_MAX (which is ^63^), but will fail the int check because
 (uint64_t)d, which is 2^63^, is strictly greater than 2^63^-1 (INT64_MAX)

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/30920#comment:22>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online