Commit a01e4a1a authored by Nick Mathewson's avatar Nick Mathewson 🥔
Browse files

kist: Cast, then do operations on int32. 

Otherwise integer overflows can happen.  Remember, doing a i32xi32
multiply doesn't actually produce a 64-bit output.  You need to do
i64xi32 or i64xi64.

Coverity found this as CID 1417753
parent 9201e4c7

src/or/scheduler_kist.c

+3 −2
Original line number Diff line number Diff line
@@ -266,7 +266,7 @@ update_socket_info_impl, (socket_table_ent_t *ent)) 


   /* Assuming all these values from the kernel are uint32_t still, they will

   * always fit into a int64_t tcp_space variable. */

  tcp_space = (ent->cwnd - ent->unacked) * ent->mss;

  tcp_space = (ent->cwnd - ent->unacked) * (int64_t)ent->mss;

  if (tcp_space < 0) {

    tcp_space = 0;

  }
@@ -277,7 +277,8 @@ update_socket_info_impl, (socket_table_ent_t *ent)) 
   * we end up negative, but then we just set extra_space to 0 in the sanity

   * check.*/

  extra_space =

    clamp_double_to_int64((ent->cwnd * ent->mss) * sock_buf_size_factor) -

    clamp_double_to_int64(

                 (ent->cwnd * (int64_t)ent->mss) * sock_buf_size_factor) -

    ent->notsent;

  if (extra_space < 0) {

    extra_space = 0;