commit 1fdf6e5814ae50ed93338644f97c65b497463141 Author: Nick Mathewson nickm@torproject.org Date: Mon Nov 7 09:58:29 2016 -0500
Avoid integer overflow in delay calculation. --- src/or/directory.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/src/or/directory.c b/src/or/directory.c index d1333a8..f83f622 100644 --- a/src/or/directory.c +++ b/src/or/directory.c @@ -3796,11 +3796,15 @@ next_random_exponential_delay(int delay, int max_delay)
/* How much are we willing to add to the delay? */ int max_increment; + const int multiplier = 4; /* no more than quintuple. */
- if (delay) - max_increment = delay * 4; /* no more than quintuple. */ - else + if (delay && delay < (INT_MAX-1) / multiplier) { + max_increment = delay * multiplier; + } else if (delay) { + max_increment = INT_MAX-1; + } else { max_increment = 1; /* we're always willing to slow down a little. */ + }
/* the + 1 here is so that we include the end of the interval */ int increment = crypto_rand_int(max_increment+1);