From 80df778bb8f868423dfe5fc9847238eee8d0a764 Mon Sep 17 00:00:00 2001
From: Michal Zalewski <lcamtuf@coredump.cx>
Date: Fri, 10 Oct 2014 11:16:06 +0100
Subject: bugfix: bash executing code following func def

This is an upstream bugfix (with slight alterations):
 Patch-ID:       bash42-053

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.

Change-Id: I660e59c76d0d50de52d48a0d399fe1dfef3bded8
---
 builtins/evalstring.c | 28 ++++++++++++++++++++++------
 parse.y               | 14 ++++++++++++--
 shell.h               |  2 ++
 y.tab.c               | 13 +++++++++++--
 4 files changed, 47 insertions(+), 10 deletions(-)

diff --git a/builtins/evalstring.c b/builtins/evalstring.c
index 61f57fc..c2bce74 100644
--- a/builtins/evalstring.c
+++ b/builtins/evalstring.c
@@ -261,12 +261,25 @@ parse_and_execute (string, from_file, flags)
 	    {
 	      struct fd_bitmap *bitmap;
 
-	      if ((flags & SEVAL_FUNCDEF) && command->type != cm_function_def)
+	      if (flags & SEVAL_FUNCDEF)
 		{
-		  internal_warning ("%s: ignoring function definition attempt", from_file);
-		  should_jump_to_top_level = 0;
-		  last_result = last_command_exit_value = EX_BADUSAGE;
-		  break;
+		  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;
+		    }
 		}
 
 	      bitmap = new_fd_bitmap (FD_BITMAP_SIZE);
@@ -331,7 +344,10 @@ parse_and_execute (string, from_file, flags)
 	      discard_unwind_frame ("pe_dispose");
 
 	      if (flags & SEVAL_ONECMD)
-		break;
+		{
+		  reset_parser ();
+		  break;
+		}
 	    }
 	}
       else
diff --git a/parse.y b/parse.y
index b3c17bc..b4ef178 100644
--- a/parse.y
+++ b/parse.y
@@ -2433,6 +2433,16 @@ shell_ungetc (c)
     eol_ungetc_lookahead = c;
 }
 
+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. */
 static void
@@ -3883,8 +3893,8 @@ xparse_dolparen (base, string, indp, flags)
 
   restore_parser_state (&ps);
   reset_parser ();
-  if (interactive)
-    token_to_read = 0;
+
+  token_to_read = 0;
 
   /* Need to find how many characters parse_and_execute consumed, update
      *indp, if flags != 0, copy the portion of the string parsed into RET
diff --git a/shell.h b/shell.h
index 92685e1..a643d80 100644
--- a/shell.h
+++ b/shell.h
@@ -167,5 +167,7 @@ typedef struct _sh_parser_state_t {
 } sh_parser_state_t;
 
 /* 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 *));
diff --git a/y.tab.c b/y.tab.c
index 677960f..f72f81e 100644
--- a/y.tab.c
+++ b/y.tab.c
@@ -4746,6 +4746,16 @@ shell_ungetc (c)
     eol_ungetc_lookahead = c;
 }
 
+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. */
 static void
@@ -6196,8 +6206,7 @@ xparse_dolparen (base, string, indp, flags)
 
   restore_parser_state (&ps);
   reset_parser ();
-  if (interactive)
-    token_to_read = 0;
+  token_to_read = 0;
 
   /* Need to find how many characters parse_and_execute consumed, update
      *indp, if flags != 0, copy the portion of the string parsed into RET
-- 
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