commit 526b0e2ce2c5d31c70eb3e48eda59b34e9eb681d Author: Nick Mathewson nickm@torproject.org Date: Wed Nov 23 13:05:22 2016 -0500

Avoid division-by-zero in pathbias_check_*_success_count --- src/or/entrynodes.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/or/entrynodes.c b/src/or/entrynodes.c index bd30078..860be9b 100644 --- a/src/or/entrynodes.c +++ b/src/or/entrynodes.c @@ -3402,10 +3402,13 @@ static void pathbias_check_use_success_count(entry_guard_t *node) { const or_options_t *options = get_options(); + const double EPSILON = 1.0e-9; + /* Note: We rely on the < comparison here to allow us to set a 0 * rate and disable the feature entirely. If refactoring, don't * change to <= */ - if (pathbias_get_use_success_count(node)/node->pb.use_attempts + if (node->pb.use_attempts > EPSILON && + pathbias_get_use_success_count(node)/node->pb.use_attempts < pathbias_get_extreme_use_rate(options) && pathbias_get_dropguards(options)) { node->pb.path_bias_disabled = 1; @@ -3420,10 +3423,13 @@ static void pathbias_check_close_success_count(entry_guard_t *node) { const or_options_t *options = get_options(); + const double EPSILON = 1.0e-9; + /* Note: We rely on the < comparison here to allow us to set a 0 * rate and disable the feature entirely. If refactoring, don't * change to <= */ - if (pathbias_get_close_success_count(node)/node->pb.circ_attempts + if (node->pb.circ_attempts > EPSILON && + pathbias_get_close_success_count(node)/node->pb.circ_attempts < pathbias_get_extreme_rate(options) && pathbias_get_dropguards(options)) { node->pb.path_bias_disabled = 1;