1. 17 Oct, 2014 1 commit
    • Daniel Borkmann's avatar
      random: add and use memzero_explicit() for clearing data · d4c5efdb
      Daniel Borkmann authored
      zatimend has reported that in his environment (3.16/gcc4.8.3/corei7)
      memset() calls which clear out sensitive data in extract_{buf,entropy,
      entropy_user}() in random driver are being optimized away by gcc.
      
      Add a helper memzero_explicit() (similarly as explicit_bzero() variants)
      that can be used in such cases where a variable with sensitive data is
      being cleared out in the end. Other use cases might also be in crypto
      code. [ I have put this into lib/string.c though, as it's always built-in
      and doesn't need any dependencies then. ]
      
      Fixes kernel bugzilla: 82041
      
      Reported-by: zatimend@hotmail.co.uk
      Signed-off-by: default avatarDaniel Borkmann <dborkman@redhat.com>
      Acked-by: default avatarHannes Frederic Sowa <hannes@stressinduktion.org>
      Cc: Alexey Dobriyan <adobriyan@gmail.com>
      Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
      Cc: stable@vger.kernel.org
      d4c5efdb
  2. 16 Aug, 2014 39 commits