[tor-bugs] #4230 [Tor Client]: smartlist functions contain bogus overflow checks

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#4230: smartlist functions contain bogus overflow checks
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 Reporter:  rransom     |          Owner:                    
     Type:  defect      |         Status:  needs_review      
 Priority:  major       |      Milestone:  Tor: 0.2.1.x-final
Component:  Tor Client  |        Version:                    
 Keywords:              |         Parent:                    
   Points:              |   Actualpoints:                    
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Comment(by asn):

 In a x86-64 system, `SIZEOF_SIZE_T == SIZEOF_INT` and `MAX_CAPACITY`
 becomes (int) (UINT_MAX / 8) == 2^29^, and MAX_CAPACITY/2 == 2^27^.

 If you pass a size bigger than 2^29^ or INT_MAX/4, it will get in the `if
 (PREDICT_UNLIKELY(size > MAX_CAPACITY/2)) {` and hit the `tor_assert(size
 <= MAX_CAPACITY);`.

 I'm not sure if this is in the function's threat model, since you have to
 pass an enormous size and it would in any case probably OOM from the
 `realloc()`, but even the original overflow of this ticket needed a huge
 size.

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/4230#comment:16>
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