Bash-4.2 Official Patch 53

[Chet Ramey]

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

Bash-Release:   4.2
Patch-ID:       bash42-053

Bug-Reported-by:        Michal Zalewski <lcamtuf@coredump.cx>
Bug-Reference-ID:
Bug-Reference-URL:

Bug-Description:

A combination of nested command substitutions and function importing from
the environment can cause bash to execute code appearing in the environment
variable value following the function definition.

Patch (apply with `patch -p0'):

*** ../bash-4.2.52/builtins/evalstring.c        2014-09-16 19:35:45.000000000 
-0400
--- builtins/evalstring.c       2014-10-04 15:00:26.000000000 -0400
***************
*** 262,271 ****
              struct fd_bitmap *bitmap;
  
!             if ((flags & SEVAL_FUNCDEF) && command->type != cm_function_def)
                {
!                 internal_warning ("%s: ignoring function definition attempt", 
from_file);
!                 should_jump_to_top_level = 0;
!                 last_result = last_command_exit_value = EX_BADUSAGE;
!                 break;
                }
  
--- 262,284 ----
              struct fd_bitmap *bitmap;
  
!             if (flags & SEVAL_FUNCDEF)
                {
!                 char *x;
! 
!                 /* If the command parses to something other than a straight
!                    function definition, or if we have not consumed the entire
!                    string, or if the parser has transformed the function
!                    name (as parsing will if it begins or ends with shell
!                    whitespace, for example), reject the attempt */
!                 if (command->type != cm_function_def ||
!                     ((x = parser_remaining_input ()) && *x) ||
!                     (STREQ (from_file, 
command->value.Function_def->name->word) == 0))
!                   {
!                     internal_warning (_("%s: ignoring function definition 
attempt"), from_file);
!                     should_jump_to_top_level = 0;
!                     last_result = last_command_exit_value = EX_BADUSAGE;
!                     reset_parser ();
!                     break;
!                   }
                }
  
***************
*** 332,336 ****
  
              if (flags & SEVAL_ONECMD)
!               break;
            }
        }
--- 345,352 ----
  
              if (flags & SEVAL_ONECMD)
!               {
!                 reset_parser ();
!                 break;
!               }
            }
        }
*** ../bash-4.2.52/parse.y      2014-09-30 19:24:19.000000000 -0400
--- parse.y     2014-10-04 15:00:26.000000000 -0400
***************
*** 2436,2439 ****
--- 2436,2449 ----
  }
  
+ char *
+ parser_remaining_input ()
+ {
+   if (shell_input_line == 0)
+     return 0;
+   if (shell_input_line_index < 0 || shell_input_line_index >= 
shell_input_line_len)
+     return '\0';      /* XXX */
+   return (shell_input_line + shell_input_line_index);
+ }
+ 
  #ifdef INCLUDE_UNUSED
  /* Back the input pointer up by one, effectively `ungetting' a character. */
***************
*** 3891,3896 ****
    /* reset_parser clears shell_input_line and associated variables */
    restore_input_line_state (&ls);
!   if (interactive)
!     token_to_read = 0;
  
    /* Need to find how many characters parse_and_execute consumed, update
--- 3901,3906 ----
    /* reset_parser clears shell_input_line and associated variables */
    restore_input_line_state (&ls);
! 
!   token_to_read = 0;
  
    /* Need to find how many characters parse_and_execute consumed, update
*** ../bash-4.2.52/shell.h      2011-11-21 18:03:32.000000000 -0500
--- shell.h     2014-10-04 15:00:26.000000000 -0400
***************
*** 178,181 ****
--- 178,183 ----
  
  /* Let's try declaring these here. */
+ extern char *parser_remaining_input __P((void));
+ 
  extern sh_parser_state_t *save_parser_state __P((sh_parser_state_t *));
  extern void restore_parser_state __P((sh_parser_state_t *));
*** ../bash-4.2-patched/patchlevel.h    Sat Jun 12 20:14:48 2010
--- patchlevel.h        Thu Feb 24 21:41:34 2011
***************
*** 26,30 ****
     looks for to find the patch level (for the sccs version string). */
  
! #define PATCHLEVEL 52
  
  #endif /* _PATCHLEVEL_H_ */
--- 26,30 ----
     looks for to find the patch level (for the sccs version string). */
  
! #define PATCHLEVEL 53
  
  #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/