bash: fix CVE-2014-6271

CVE-2014-6271 aka ShellShock.

"GNU Bash through 4.3 processes trailing strings after function definitions in
the values of environment variables, which allows remote attackers to execute
arbitrary code via a crafted environment."

(From OE-Core rev: 798d833c9d4bd9ab287fa86b85b4d5f128170ed3)

Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 114 insertions, 0 deletions

diff --git a/meta/recipes-extended/bash/bash/cve-2014-6271.patch b/meta/recipes-extended/bash/bash/cve-2014-6271.patch
new file mode 100644
index 0000000000..d33a5c8f47
--- /dev/null
+++ b/meta/recipes-extended/bash/bash/cve-2014-6271.patch
@@ -0,0 +1,114 @@
+Fix CVE-2014-6271, aka ShellShock.  This is the upstream 4.3 patchlevel 25, minus the hunk to
+set the patch level.
+
+Upstream-Status: Backport
+Signed-off-by: Ross Burton <ross.burton@intel.com>
+
+                             BASH PATCH REPORT
+                             =================
+
+Bash-Release:   4.3
+Patch-ID:       bash43-025
+
+Bug-Reported-by:        Stephane Chazelas <stephane.chazelas@gmail.com>
+Bug-Reference-ID:
+Bug-Reference-URL:
+
+Bug-Description:
+
+Under certain circumstances, bash will execute user code while processing the
+environment for exported function definitions.
+
+Patch (apply with `patch -p0'):
+
+*** ../bash-4.3-patched/builtins/common.h       2013-07-08 16:54:47.000000000 -0400
+--- builtins/common.h   2014-09-12 14:25:47.000000000 -0400
+***************
+*** 34,37 ****
+--- 49,54 ----
+  #define SEVAL_PARSEONLY       0x020
+  #define SEVAL_NOLONGJMP 0x040
++ #define SEVAL_FUNCDEF 0x080           /* only allow function definitions */
++ #define SEVAL_ONECMD  0x100           /* only allow a single command */
+  
+  /* Flags for describe_command, shared between type.def and command.def */
+*** ../bash-4.3-patched/builtins/evalstring.c   2014-02-11 09:42:10.000000000 -0500
+--- builtins/evalstring.c       2014-09-14 14:15:13.000000000 -0400
+***************
+*** 309,312 ****
+--- 313,324 ----
+              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;
++               }
++ 
+              bitmap = new_fd_bitmap (FD_BITMAP_SIZE);
+              begin_unwind_frame ("pe_dispose");
+***************
+*** 369,372 ****
+--- 381,387 ----
+              dispose_fd_bitmap (bitmap);
+              discard_unwind_frame ("pe_dispose");
++ 
++             if (flags & SEVAL_ONECMD)
++               break;
+            }
+        }
+*** ../bash-4.3-patched/variables.c     2014-05-15 08:26:50.000000000 -0400
+--- variables.c 2014-09-14 14:23:35.000000000 -0400
+***************
+*** 359,369 ****
+          strcpy (temp_string + char_index + 1, string);
+  
+!         if (posixly_correct == 0 || legal_identifier (name))
+!           parse_and_execute (temp_string, name, SEVAL_NONINT|SEVAL_NOHIST);
+! 
+!         /* Ancient backwards compatibility.  Old versions of bash exported
+!            functions like name()=() {...} */
+!         if (name[char_index - 1] == ')' && name[char_index - 2] == '(')
+!           name[char_index - 2] = '\0';
+  
+          if (temp_var = find_function (name))
+--- 364,372 ----
+          strcpy (temp_string + char_index + 1, string);
+  
+!         /* Don't import function names that are invalid identifiers from the
+!            environment, though we still allow them to be defined as shell
+!            variables. */
+!         if (legal_identifier (name))
+!           parse_and_execute (temp_string, name, SEVAL_NONINT|SEVAL_NOHIST|SEVAL_FUNCDEF|SEVAL_ONECMD);
+  
+          if (temp_var = find_function (name))
+***************
+*** 382,389 ****
+              report_error (_("error importing function definition for `%s'"), name);
+            }
+- 
+-         /* ( */
+-         if (name[char_index - 1] == ')' && name[char_index - 2] == '\0')
+-           name[char_index - 2] = '(';         /* ) */
+        }
+  #if defined (ARRAY_VARS)
+--- 385,388 ----
+*** ../bash-4.3-patched/subst.c 2014-08-11 11:16:35.000000000 -0400
+--- subst.c     2014-09-12 15:31:04.000000000 -0400
+***************
+*** 8048,8052 ****
+          goto return0;
+        }
+!       else if (var = find_variable_last_nameref (temp1))
+        {
+          temp = nameref_cell (var);
+--- 8118,8124 ----
+          goto return0;
+        }
+!       else if (var && (invisible_p (var) || var_isset (var) == 0))
+!       temp = (char *)NULL;
+!       else if ((var = find_variable_last_nameref (temp1)) && var_isset (var) && invisible_p (var) == 0)
+        {
+          temp = nameref_cell (var);