Commit 719940df authored Feb 11, 2013 by Nick Mathewson

Fix a nigh-impossible overflow in cpuworker.c

When we compute the estimated microseconds we need to handle our
pending onionskins, we could (in principle) overflow a uint32_t if
we ever had 4 million pending onionskins before we had any data
about how onionskins take.  Nevertheless, let's compute it properly.

Fixes bug 8210; bugfix on 0.2.4.10. Found by coverity; this is CID
980651.

parent 9b2bb901

changes/bug8210

0 → 100644

+6 −0

Original line number	Diff line number	Diff line
		o Minor bugfixes:
		- Fix an impossible-to-trigger integer overflow when
		estimating how long out onionskin queue would take. (This overflow
		would require us to accept 4 million onionskins before processing
		100 of them.) Fixes bug 8210; bugfix on 0.2.4.10-alpha.

src/or/cpuworker.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -222,10 +222,10 @@ uint64_t
		estimated_usec_for_onionskins(uint32_t n_requests, uint16_t onionskin_type)
		{
		if (onionskin_type > MAX_ONION_HANDSHAKE_TYPE) /* should be impossible */
		return 1000 * n_requests;
		return 1000 * (uint64_t)n_requests;
		if (PREDICT_UNLIKELY(onionskins_n_processed[onionskin_type] < 100)) {
		/* Until we have 100 data points, just asssume everything takes 1 msec. */
		return 1000 * n_requests;
		return 1000 * (uint64_t)n_requests;
		} else {
		/* This can't overflow: we'll never have more than 500000 onionskins
		* measured in onionskin_usec_internal, and they won't take anything near