commit 77459b97aac15949c5160ca8abb9af792f02ac73 Author: Ivan Markin twim@riseup.net Date: Fri Jun 17 03:44:58 2016 +0000

Fix integer overflow in the rate-limiter (#19435). --- changes/bug19435 | 6 ++++++ src/common/util.c | 14 ++++++++++++-- src/common/util.h | 1 + 3 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/changes/bug19435 b/changes/bug19435 new file mode 100644 index 0000000..ccd916b --- /dev/null +++ b/changes/bug19435 @@ -0,0 +1,6 @@ + o Major bugfixes (user interface): + - Fix an integer overflow in the rate-limiter that caused displaying of + wrong number of suppressed messages (if there are too many of them). + If the number of messages hits the limit of messages per interval the + rate-limiter drops a warning and doesn't count any further. + Fixes bug 19435. diff --git a/src/common/util.c b/src/common/util.c index 538aeb1..72efd89 100644 --- a/src/common/util.c +++ b/src/common/util.c @@ -1983,7 +1983,9 @@ update_approx_time(time_t now)

/** If the rate-limiter <b>lim</b> is ready at <b>now</b>, return the number * of calls to rate_limit_is_ready (including this one!) since the last time - * rate_limit_is_ready returned nonzero. Otherwise return 0. */ + * rate_limit_is_ready returned nonzero. Otherwise return 0. + * If the call number hits <b>RATELIM_TOOMANY</b> limit, drop a warning + * about this event and stop counting. */ static int rate_limit_is_ready(ratelim_t *lim, time_t now) { @@ -1993,7 +1995,15 @@ rate_limit_is_ready(ratelim_t *lim, time_t now) lim->n_calls_since_last_time = 0; return res; } else { - ++lim->n_calls_since_last_time; + if (lim->n_calls_since_last_time < RATELIM_TOOMANY) { + ++lim->n_calls_since_last_time; + } else if (lim->n_calls_since_last_time == RATELIM_TOOMANY) { + log_warn(LD_GENERAL, + "Enormously large number of messages (%d). It's probably a bug.", + RATELIM_TOOMANY); + ++lim->n_calls_since_last_time; + } + return 0; } } diff --git a/src/common/util.h b/src/common/util.h index 0d48eac..837d2e9 100644 --- a/src/common/util.h +++ b/src/common/util.h @@ -292,6 +292,7 @@ typedef struct ratelim_t { } ratelim_t;

#define RATELIM_INIT(r) { (r), 0, 0 } +#define RATELIM_TOOMANY (16*1000)

char *rate_limit_log(ratelim_t *lim, time_t now);