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

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#30920: Detect uint64 overflow in config_parse_units()
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 Reporter:  nickm          |          Owner:  (none)
     Type:  defect         |         Status:  new
 Priority:  Low            |      Milestone:  Tor: 0.4.2.x-final
Component:  Core Tor/Tor   |        Version:
 Severity:  Minor          |     Resolution:
 Keywords:  easy overflow  |  Actual Points:
Parent ID:                 |         Points:
 Reviewer:                 |        Sponsor:
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Comment (by guigom):

 I haven't opened a PR yet but my branch for this ticket is in
 [https://github.com/JMGuisadoG/tor/tree/ticket30920]

 * Commit adding the u64_nowrap_mul & tests:
 [https://github.com/JMGuisadoG/tor/commit/4dd5b593636a9f5944ca2069d1c22c2b4b03d335]

 * Commit adding the check for overflow inside mem_parse_units & enabling
 tests:
 [https://github.com/JMGuisadoG/tor/commit/1ac4b346131fa0f49a5218553cd5d98affb82a76]

 Replying to [comment:11 teor]:
 > Maybe we should fail on anything larger than SSIZE_T_MAX?
 > (SSIZE_T_MAX is half the maximum possible memory size.)

 What the reason for checking half the maximum size?.

 If that's a go and there's no problem with the code above I can change the
 if statement accordingly.

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/30920#comment:12>
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