1. 07 Aug, 2020 1 commit
    • Willy Tarreau's avatar
      random32: update the net random state on interrupt and activity · 29204c84
      Willy Tarreau authored
      commit f227e3ec upstream.
      
      This modifies the first 32 bits out of the 128 bits of a random CPU's
      net_rand_state on interrupt or CPU activity to complicate remote
      observations that could lead to guessing the network RNG's internal
      state.
      
      Note that depending on some network devices' interrupt rate moderation
      or binding, this re-seeding might happen on every packet or even almost
      never.
      
      In addition, with NOHZ some CPUs might not even get timer interrupts,
      leaving their local state rarely updated, while they are running
      networked processes making use of the random state.  For this reason, we
      also perform this update in update_process_times() in order to at least
      update the state when there is user or system activity, since it's the
      only case we care about.
      Reported-by: default avatarAmit Klein <aksecurity@gmail.com>
      Suggested-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Cc: Eric Dumazet <edumazet@google.com>
      Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Kees Cook <keescook@chromium.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      29204c84
  2. 05 Aug, 2020 39 commits