Author: cem
Date: Fri Oct 26 20:55:01 2018
New Revision: 339788
URL: https://svnweb.freebsd.org/changeset/base/339788

Log:
  Fortuna: fix a correctness issue in reseed (fortuna_pre_read)
  
  'i' counts the number of pools included in the array 's'.  Passing 'i+1' to
  reseed_internal() as the number of blocks in 's' is a bogus overrun of the
  initialized portion of 's' -- technically UB.
  
  I found this via code inspection, referencing ยง9.5.2 "Pools" of the Fortuna
  chapter, but I would expect Coverity to notice the same issue.
  Unfortunately, it doesn't appear to.
  
  Reviewed by:  markm
  Approved by:  secteam (gordon)
  Sponsored by: Dell EMC Isilon
  Differential Revision:        https://reviews.freebsd.org/D16985

Modified:
  head/sys/dev/random/fortuna.c

Modified: head/sys/dev/random/fortuna.c
==============================================================================
--- head/sys/dev/random/fortuna.c       Fri Oct 26 20:53:01 2018        
(r339787)
+++ head/sys/dev/random/fortuna.c       Fri Oct 26 20:55:01 2018        
(r339788)
@@ -408,7 +408,7 @@ random_fortuna_pre_read(void)
                SDT_PROBE2(random, fortuna, event_processor, debug, 
fortuna_state.fs_reseedcount, fortuna_state.fs_pool);
 #endif
                /* FS&K */
-               random_fortuna_reseed_internal(s, i < RANDOM_FORTUNA_NPOOLS ? i 
+ 1 : RANDOM_FORTUNA_NPOOLS);
+               random_fortuna_reseed_internal(s, i);
                /* Clean up and secure */
                explicit_bzero(s, sizeof(s));
                explicit_bzero(temp, sizeof(temp));
_______________________________________________
svn-src-all@freebsd.org mailing list
https://lists.freebsd.org/mailman/listinfo/svn-src-all
To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"

Reply via email to