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| author | Nick Mathewson <nickm@torproject.org> | 2013-02-11 16:40:48 -0500 |
|---|---|---|
| committer | Nick Mathewson <nickm@torproject.org> | 2013-02-11 16:46:38 -0500 |
| commit | 719940df2bdfbd0f5ee02a9ca404f345d2fc49e8 (patch) | |
| tree | 9e0a1eb4df791ee2265f413877f7d036493a8507 | |
| parent | 9b2bb901d7c306fd6ca28de527e86379470db89a (diff) | |
| download | tor-719940df2bdfbd0f5ee02a9ca404f345d2fc49e8.tar tor-719940df2bdfbd0f5ee02a9ca404f345d2fc49e8.tar.gz | |
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.
| -rw-r--r-- | changes/bug8210 | 6 | ||||
| -rw-r--r-- | src/or/cpuworker.c | 4 |
2 files changed, 8 insertions, 2 deletions
diff --git a/changes/bug8210 b/changes/bug8210 new file mode 100644 index 000000000..85d41b844 --- /dev/null +++ b/changes/bug8210 @@ -0,0 +1,6 @@ + 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. + diff --git a/src/or/cpuworker.c b/src/or/cpuworker.c index 6b52f3b5d..444f17cd4 100644 --- a/src/or/cpuworker.c +++ b/src/or/cpuworker.c @@ -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 |