Bash-3.1 Official Patch 21

[Chet Ramey]

                             BASH PATCH REPORT
                             =================

Bash-Release: 3.1
Patch-ID: bash31-021

Bug-Reported-by:        Florian Weimer <fweimer@redhat.com>
Bug-Reference-ID:
Bug-Reference-URL:

Bug-Description:

There are two local buffer overflows in parse.y that can cause the shell
to dump core when given many here-documents attached to a single command
or many nested loops.

Patch:

*** ../bash-3.1.20/parse.y      2014-09-27 12:16:39.000000000 -0400
--- parse.y     2014-09-30 19:49:41.000000000 -0400
***************
*** 167,170 ****
--- 167,173 ----
  static int reserved_word_acceptable __P((int));
  static int yylex __P((void));
+ 
+ static void push_heredoc __P((REDIRECT *));
+ static char *mk_alexpansion __P((char *));
  static int alias_expand_token __P((char *));
  static int time_command_acceptable __P((void));
***************
*** 259,263 ****
  /* Variables to manage the task of reading here documents, because we need to
     defer the reading until after a complete command has been collected. */
! static REDIRECT *redir_stack[10];
  int need_here_doc;
  
--- 262,268 ----
  /* Variables to manage the task of reading here documents, because we need to
     defer the reading until after a complete command has been collected. */
! #define HEREDOC_MAX 16
! 
! static REDIRECT *redir_stack[HEREDOC_MAX];
  int need_here_doc;
  
***************
*** 285,289 ****
     index is decremented after a case, select, or for command is parsed. */
  #define MAX_CASE_NEST 128
! static int word_lineno[MAX_CASE_NEST];
  static int word_top = -1;
  
--- 290,294 ----
     index is decremented after a case, select, or for command is parsed. */
  #define MAX_CASE_NEST 128
! static int word_lineno[MAX_CASE_NEST+1];
  static int word_top = -1;
  
***************
*** 430,434 ****
                          redir.filename = $2;
                          $$ = make_redirection (0, r_reading_until, redir);
!                         redir_stack[need_here_doc++] = $$;
                        }
        |       NUMBER LESS_LESS WORD
--- 435,439 ----
                          redir.filename = $2;
                          $$ = make_redirection (0, r_reading_until, redir);
!                         push_heredoc ($$);
                        }
        |       NUMBER LESS_LESS WORD
***************
*** 436,440 ****
                          redir.filename = $3;
                          $$ = make_redirection ($1, r_reading_until, redir);
!                         redir_stack[need_here_doc++] = $$;
                        }
        |       LESS_LESS_LESS WORD
--- 441,445 ----
                          redir.filename = $3;
                          $$ = make_redirection ($1, r_reading_until, redir);
!                         push_heredoc ($$);
                        }
        |       LESS_LESS_LESS WORD
***************
*** 493,497 ****
                          $$ = make_redirection
                            (0, r_deblank_reading_until, redir);
!                         redir_stack[need_here_doc++] = $$;
                        }
        |       NUMBER LESS_LESS_MINUS WORD
--- 498,502 ----
                          $$ = make_redirection
                            (0, r_deblank_reading_until, redir);
!                         push_heredoc ($$);
                        }
        |       NUMBER LESS_LESS_MINUS WORD
***************
*** 500,504 ****
                          $$ = make_redirection
                            ($1, r_deblank_reading_until, redir);
!                         redir_stack[need_here_doc++] = $$;
                        }
        |       GREATER_AND '-'
--- 505,509 ----
                          $$ = make_redirection
                            ($1, r_deblank_reading_until, redir);
!                         push_heredoc ($$);
                        }
        |       GREATER_AND '-'
***************
*** 2211,2214 ****
--- 2216,2234 ----
  static int esacs_needed_count;
  
+ static void
+ push_heredoc (r)
+      REDIRECT *r;
+ {
+   if (need_here_doc >= HEREDOC_MAX)
+     {
+       last_command_exit_value = EX_BADUSAGE;
+       need_here_doc = 0;
+       report_syntax_error (_("maximum here-document count exceeded"));
+       reset_parser ();
+       exit_shell (last_command_exit_value);
+     }
+   redir_stack[need_here_doc++] = r;
+ }
+ 
  void
  gather_here_documents ()
*** ../bash-3.1/patchlevel.h    Wed Jul 20 13:58:20 2005
--- patchlevel.h        Wed Dec  7 13:48:42 2005
***************
*** 26,30 ****
     looks for to find the patch level (for the sccs version string). */
  
! #define PATCHLEVEL 20
  
  #endif /* _PATCHLEVEL_H_ */
--- 26,30 ----
     looks for to find the patch level (for the sccs version string). */
  
! #define PATCHLEVEL 21
  
  #endif /* _PATCHLEVEL_H_ */

-- 
``The lyf so short, the craft so long to lerne.'' - Chaucer
                 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, ITS, CWRU    chet@case.edu    http://cnswww.cns.cwru.edu/~chet/