commit 68caa834f4ed9cae16a551c9fc63ea982c9f1904 Author: Nick Mathewson nickm@torproject.org Date: Fri Sep 14 10:10:16 2012 -0400

document why we only allow 64 flags in votes --- src/or/routerparse.c | 5 +++++ 1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/src/or/routerparse.c b/src/or/routerparse.c index 496b90d..43a95e8 100644 --- a/src/or/routerparse.c +++ b/src/or/routerparse.c @@ -3006,6 +3006,11 @@ networkstatus_parse_vote_from_string(const char *s, const char **eos_out, } if (ns->type != NS_TYPE_CONSENSUS && smartlist_len(ns->known_flags) > MAX_KNOWN_FLAGS_IN_VOTE) { + /* If we allowed more than 64 flags in votes, then parsing them would make + * us invoke undefined behavior whenever we used 1<<flagnum to do a + * bit-shift. This is only for votes and opinions: consensus users don't + * care about flags they don't recognize, and so don't build a bitfield + * for them. */ log_warn(LD_DIR, "Too many known-flags in consensus vote or opinion"); goto err; }