bash: fix CVE-2014-6271
authorRoss Burton <ross.burton@intel.com>
Thu, 25 Sep 2014 23:05:18 +0000 (00:05 +0100)
committerRichard Purdie <richard.purdie@linuxfoundation.org>
Mon, 29 Sep 2014 11:12:46 +0000 (12:12 +0100)
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>
meta/recipes-extended/bash/bash-3.2.48/cve-2014-6271.patch [new file with mode: 0644]
meta/recipes-extended/bash/bash/cve-2014-6271.patch [new file with mode: 0644]
meta/recipes-extended/bash/bash_3.2.48.bb
meta/recipes-extended/bash/bash_4.3.bb

diff --git a/meta/recipes-extended/bash/bash-3.2.48/cve-2014-6271.patch b/meta/recipes-extended/bash/bash-3.2.48/cve-2014-6271.patch
new file mode 100644 (file)
index 0000000..7226ffb
--- /dev/null
@@ -0,0 +1,77 @@
+Fix CVE-2014-6271, aka ShellShock.
+
+Upstream-Status: Backport
+Signed-off-by: Ross Burton <ross.burton@intel.com>
+
+*** ../bash-3.2.51/builtins/common.h   2006-03-06 09:38:44.000000000 -0500
+--- builtins/common.h  2014-09-16 19:08:02.000000000 -0400
+***************
+*** 34,37 ****
+--- 34,39 ----
+  
+  /* 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-3.2.51/builtins/evalstring.c       2008-11-15 17:47:04.000000000 -0500
+--- builtins/evalstring.c      2014-09-16 19:08:02.000000000 -0400
+***************
+*** 235,238 ****
+--- 235,246 ----
+             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");
+***************
+*** 292,295 ****
+--- 300,306 ----
+             dispose_fd_bitmap (bitmap);
+             discard_unwind_frame ("pe_dispose");
++ 
++            if (flags & SEVAL_ONECMD)
++              break;
+           }
+       }
+*** ../bash-3.2.51/variables.c 2008-11-15 17:15:06.000000000 -0500
+--- variables.c        2014-09-16 19:10:39.000000000 -0400
+***************
+*** 319,328 ****
+         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))
+--- 319,326 ----
+         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))
+***************
+*** 333,340 ****
+         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)
+--- 331,334 ----
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 (file)
index 0000000..d33a5c8
--- /dev/null
@@ -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);
index fe04b28..5849ed0 100644 (file)
@@ -12,6 +12,7 @@ SRC_URI = "${GNU_MIRROR}/bash/bash-${PV}.tar.gz;name=tarball \
            file://mkbuiltins_have_stringize.patch \
            file://build-tests.patch \
            file://test-output.patch \
+           file://cve-2014-6271.patch;striplevel=0 \
            file://run-ptest \
           "
 
index 25b7410..febaf33 100644 (file)
@@ -9,6 +9,7 @@ SRC_URI = "${GNU_MIRROR}/bash/${BPN}-${PV}.tar.gz;name=tarball \
            file://mkbuiltins_have_stringize.patch \
            file://build-tests.patch \
            file://test-output.patch \
+           file://cve-2014-6271.patch;striplevel=0 \
            file://run-ptest \
            "