1
0
mirror of https://git.yoctoproject.org/poky synced 2026-05-09 05:29:32 +00:00

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>
This commit is contained in:
Ross Burton
2014-09-26 00:05:18 +01:00
committed by Richard Purdie
parent cf9fbf53b9
commit 215e7b98ae
4 changed files with 193 additions and 0 deletions
@@ -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 ----
@@ -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);
@@ -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 \
"
+1
View 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 \
"