dbus: fix CVE-2022-42010 Check brackets in signature nest correctly

Signed-off-by: Xiangyu Chen <xiangyu.chen@eng.windriver.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>

1 files changed, 119 insertions, 0 deletions

diff --git a/meta/recipes-core/dbus/dbus/0001-dbus-marshal-validate-Check-brackets-in-signature-ne.patch b/meta/recipes-core/dbus/dbus/0001-dbus-marshal-validate-Check-brackets-in-signature-ne.patch
new file mode 100644
index 0000000000..f2e14fb8d5
--- /dev/null
+++ b/meta/recipes-core/dbus/dbus/0001-dbus-marshal-validate-Check-brackets-in-signature-ne.patch
@@ -0,0 +1,119 @@
+From 3e53a785dee8d1432156188a2c4260e4cbc78c4d Mon Sep 17 00:00:00 2001
+From: Simon McVittie <smcv@collabora.com>
+Date: Tue, 13 Sep 2022 15:10:22 +0100
+Subject: [PATCH] dbus-marshal-validate: Check brackets in signature nest
+ correctly
+
+In debug builds with assertions enabled, a signature with incorrectly
+nested `()` and `{}`, for example `a{i(u}` or `(a{ii)}`, could result
+in an assertion failure.
+
+In production builds without assertions enabled, a signature with
+incorrectly nested `()` and `{}` could potentially result in a crash
+or incorrect message parsing, although we do not have a concrete example
+of either of these failure modes.
+
+Thanks: Evgeny Vereshchagin
+Resolves: https://gitlab.freedesktop.org/dbus/dbus/-/issues/418
+Resolves: CVE-2022-42010
+
+Upstream-Status: Backport [https://gitlab.freedesktop.org/dbus/dbus/-/commit/3e53a785dee8d1432156188a2c4260e4cbc78c4d]
+
+Signed-off-by: Simon McVittie <smcv@collabora.com>
+(cherry picked from commit 9d07424e9011e3bbe535e83043d335f3093d2916)
+Signed-off-by: Xiangyu Chen <xiangyu.chen@eng.windriver.com>
+---
+ dbus/dbus-marshal-validate.c | 38 +++++++++++++++++++++++++++++++++++-
+ 1 file changed, 37 insertions(+), 1 deletion(-)
+
+diff --git a/dbus/dbus-marshal-validate.c b/dbus/dbus-marshal-validate.c
+index 4d492f3f..ae68414d 100644
+--- a/dbus/dbus-marshal-validate.c
++++ b/dbus/dbus-marshal-validate.c
+@@ -62,6 +62,8 @@ _dbus_validate_signature_with_reason (const DBusString *type_str,
+ 
+   int element_count;
+   DBusList *element_count_stack;
++  char opened_brackets[DBUS_MAXIMUM_TYPE_RECURSION_DEPTH * 2 + 1] = { '\0' };
++  char last_bracket;
+ 
+   result = DBUS_VALID;
+   element_count_stack = NULL;
+@@ -93,6 +95,10 @@ _dbus_validate_signature_with_reason (const DBusString *type_str,
+ 
+   while (p != end)
+     {
++      _dbus_assert (struct_depth + dict_entry_depth >= 0);
++      _dbus_assert (struct_depth + dict_entry_depth < _DBUS_N_ELEMENTS (opened_brackets));
++      _dbus_assert (opened_brackets[struct_depth + dict_entry_depth] == '\0');
++
+       switch (*p)
+         {
+         case DBUS_TYPE_BYTE:
+@@ -136,6 +142,10 @@ _dbus_validate_signature_with_reason (const DBusString *type_str,
+               goto out;
+             }
+ 
++          _dbus_assert (struct_depth + dict_entry_depth >= 1);
++          _dbus_assert (struct_depth + dict_entry_depth < _DBUS_N_ELEMENTS (opened_brackets));
++          _dbus_assert (opened_brackets[struct_depth + dict_entry_depth - 1] == '\0');
++          opened_brackets[struct_depth + dict_entry_depth - 1] = DBUS_STRUCT_BEGIN_CHAR;
+           break;
+ 
+         case DBUS_STRUCT_END_CHAR:
+@@ -151,9 +161,20 @@ _dbus_validate_signature_with_reason (const DBusString *type_str,
+               goto out;
+             }
+ 
++          _dbus_assert (struct_depth + dict_entry_depth >= 1);
++          _dbus_assert (struct_depth + dict_entry_depth < _DBUS_N_ELEMENTS (opened_brackets));
++          last_bracket = opened_brackets[struct_depth + dict_entry_depth - 1];
++
++          if (last_bracket != DBUS_STRUCT_BEGIN_CHAR)
++            {
++              result = DBUS_INVALID_STRUCT_ENDED_BUT_NOT_STARTED;
++              goto out;
++            }
++
+           _dbus_list_pop_last (&element_count_stack);
+ 
+           struct_depth -= 1;
++          opened_brackets[struct_depth + dict_entry_depth] = '\0';
+           break;
+ 
+         case DBUS_DICT_ENTRY_BEGIN_CHAR:
+@@ -178,6 +199,10 @@ _dbus_validate_signature_with_reason (const DBusString *type_str,
+               goto out;
+             }
+ 
++          _dbus_assert (struct_depth + dict_entry_depth >= 1);
++          _dbus_assert (struct_depth + dict_entry_depth < _DBUS_N_ELEMENTS (opened_brackets));
++          _dbus_assert (opened_brackets[struct_depth + dict_entry_depth - 1] == '\0');
++          opened_brackets[struct_depth + dict_entry_depth - 1] = DBUS_DICT_ENTRY_BEGIN_CHAR;
+           break;
+ 
+         case DBUS_DICT_ENTRY_END_CHAR:
+@@ -186,8 +211,19 @@ _dbus_validate_signature_with_reason (const DBusString *type_str,
+               result = DBUS_INVALID_DICT_ENTRY_ENDED_BUT_NOT_STARTED;
+               goto out;
+             }
+-            
++
++          _dbus_assert (struct_depth + dict_entry_depth >= 1);
++          _dbus_assert (struct_depth + dict_entry_depth < _DBUS_N_ELEMENTS (opened_brackets));
++          last_bracket = opened_brackets[struct_depth + dict_entry_depth - 1];
++
++          if (last_bracket != DBUS_DICT_ENTRY_BEGIN_CHAR)
++            {
++              result = DBUS_INVALID_DICT_ENTRY_ENDED_BUT_NOT_STARTED;
++              goto out;
++            }
++
+           dict_entry_depth -= 1;
++          opened_brackets[struct_depth + dict_entry_depth] = '\0';
+ 
+           element_count = 
+             _DBUS_POINTER_TO_INT (_dbus_list_pop_last (&element_count_stack));
+-- 
+2.34.1
+