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 master rev: 798d833c9d4bd9ab287fa86b85b4d5f128170ed3)

(From OE-Core rev: d57b9ce8bb97f88c329da973c3567d04d8eb07d2)

Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Robert Yang <liezhi.yang@windriver.com>
Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 95 insertions, 0 deletions

diff --git a/meta/recipes-extended/bash/bash-4.2/cve-2014-6271.patch b/meta/recipes-extended/bash/bash-4.2/cve-2014-6271.patch
new file mode 100644
index 0000000000..20530adf6c
--- /dev/null
+++ b/meta/recipes-extended/bash/bash-4.2/cve-2014-6271.patch
@@ -0,0 +1,95 @@
+Fix CVE-2014-6271, aka ShellShock.  This is the upstream 4.2 patchlevel 48, minus the hunk to
+set the patch level.
+
+Upstream-Status: Backport
+Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>
+
+                             BASH PATCH REPORT
+                             =================
+
+Bash-Release:   4.2
+Patch-ID:       bash42-048
+
+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-4.2.47/builtins/common.h    2010-05-30 18:31:51.000000000 -0400
+--- builtins/common.h   2014-09-16 19:35:45.000000000 -0400
+***************
+*** 36,39 ****
+--- 36,41 ----
+  
+  /* Flags for describe_command, shared between type.def and command.def */
++ #define SEVAL_FUNCDEF 0x080           /* only allow function definitions */
++ #define SEVAL_ONECMD  0x100           /* only allow a single command */
+  #define CDESC_ALL             0x001   /* type -a */
+  #define CDESC_SHORTDESC               0x002   /* command -V */
+*** ../bash-4.2.47/builtins/evalstring.c        2010-11-23 08:22:15.000000000 -0500
+--- builtins/evalstring.c       2014-09-16 19:35:45.000000000 -0400
+***************
+*** 262,265 ****
+--- 262,273 ----
+              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");
+***************
+*** 322,325 ****
+--- 330,336 ----
+              dispose_fd_bitmap (bitmap);
+              discard_unwind_frame ("pe_dispose");
++ 
++             if (flags & SEVAL_ONECMD)
++               break;
+            }
+        }
+*** ../bash-4.2.47/variables.c  2011-03-01 16:15:20.000000000 -0500
+--- variables.c 2014-09-16 19:35:45.000000000 -0400
+***************
+*** 348,357 ****
+          strcpy (temp_string + char_index + 1, string);
+  
+!         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))
+--- 348,355 ----
+          strcpy (temp_string + char_index + 1, string);
+  
+!         /* Don't import function names that are invalid identifiers from the
+!            environment. */
+!         if (legal_identifier (name))
+!           parse_and_execute (temp_string, name, SEVAL_NONINT|SEVAL_NOHIST|SEVAL_FUNCDEF|SEVAL_ONECMD);
+  
+          if (temp_var = find_function (name))
+***************
+*** 362,369 ****
+          else
+            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)
+--- 360,363 ----