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authorLennart Poettering <lennart@poettering.net>2012-10-03 13:29:20 -0400
committerLennart Poettering <lennart@poettering.net>2012-10-03 13:29:20 -0400
commit0b507b17a760b21e33fc52ff377db6aa5086c680 (patch)
tree472861f8e6dd3b70752b26feded8e0246e1103d9
parent07c289875fd46331a430c43e8991d3c7407cb703 (diff)
dbus: add some more safety checks before accepting data from bus clients
-rw-r--r--src/hostname/hostnamed.c8
-rw-r--r--src/journal/journald-native.c2
-rw-r--r--src/locale/localed.c14
-rw-r--r--src/shared/util.c37
-rw-r--r--src/shared/util.h3
5 files changed, 62 insertions, 2 deletions
diff --git a/src/hostname/hostnamed.c b/src/hostname/hostnamed.c
index 8f9d5a04f5..cd3ef491ac 100644
--- a/src/hostname/hostnamed.c
+++ b/src/hostname/hostnamed.c
@@ -451,6 +451,14 @@ static DBusHandlerResult hostname_message_handler(
} else {
char *h;
+ /* The icon name might ultimately be
+ * used as file name, so better be
+ * safe than sorry */
+ if (k == PROP_ICON_NAME && !filename_is_safe(name))
+ return bus_send_error_reply(connection, message, NULL, -EINVAL);
+ if (k == PROP_PRETTY_HOSTNAME && !string_is_safe(name))
+ return bus_send_error_reply(connection, message, NULL, -EINVAL);
+
h = strdup(name);
if (!h)
goto oom;
diff --git a/src/journal/journald-native.c b/src/journal/journald-native.c
index 12fb980dd6..de8d6998cf 100644
--- a/src/journal/journald-native.c
+++ b/src/journal/journald-native.c
@@ -314,7 +314,7 @@ void server_process_native_file(
return;
}
- if (strchr(e, '/')) {
+ if (!filename_is_safe(e)) {
log_error("Received file in subdirectory of allowed directories. Refusing.");
return;
}
diff --git a/src/locale/localed.c b/src/locale/localed.c
index a2d381406c..04268a1982 100644
--- a/src/locale/localed.c
+++ b/src/locale/localed.c
@@ -1039,7 +1039,9 @@ static DBusHandlerResult locale_message_handler(
size_t k;
k = strlen(names[p]);
- if (startswith(*i, names[p]) && (*i)[k] == '=') {
+ if (startswith(*i, names[p]) &&
+ (*i)[k] == '=' &&
+ string_is_safe((*i) + k + 1)) {
valid = true;
passed[p] = true;
@@ -1150,6 +1152,10 @@ static DBusHandlerResult locale_message_handler(
if (!streq_ptr(keymap, state.vc_keymap) ||
!streq_ptr(keymap_toggle, state.vc_keymap_toggle)) {
+ if ((keymap && (!filename_is_safe(keymap) || !string_is_safe(keymap))) ||
+ (keymap_toggle && (!filename_is_safe(keymap_toggle) || !string_is_safe(keymap_toggle))))
+ return bus_send_error_reply(connection, message, NULL, -EINVAL);
+
r = verify_polkit(connection, message, "org.freedesktop.locale1.set-keyboard", interactive, NULL, &error);
if (r < 0)
return bus_send_error_reply(connection, message, &error, r);
@@ -1220,6 +1226,12 @@ static DBusHandlerResult locale_message_handler(
!streq_ptr(variant, state.x11_variant) ||
!streq_ptr(options, state.x11_options)) {
+ if ((layout && !string_is_safe(layout)) ||
+ (model && !string_is_safe(model)) ||
+ (variant && !string_is_safe(variant)) ||
+ (options && !string_is_safe(options)))
+ return bus_send_error_reply(connection, message, NULL, -EINVAL);
+
r = verify_polkit(connection, message, "org.freedesktop.locale1.set-keyboard", interactive, NULL, &error);
if (r < 0)
return bus_send_error_reply(connection, message, &error, r);
diff --git a/src/shared/util.c b/src/shared/util.c
index d2ca3fc783..64d6e62a53 100644
--- a/src/shared/util.c
+++ b/src/shared/util.c
@@ -56,6 +56,7 @@
#include <sys/mman.h>
#include <sys/vfs.h>
#include <linux/magic.h>
+#include <limits.h>
#include "macro.h"
#include "util.h"
@@ -5851,3 +5852,39 @@ void closedirp(DIR **d) {
void umaskp(mode_t *u) {
umask(*u);
}
+
+bool filename_is_safe(const char *p) {
+
+ if (isempty(p))
+ return false;
+
+ if (strchr(p, '/'))
+ return false;
+
+ if (streq(p, "."))
+ return false;
+
+ if (streq(p, ".."))
+ return false;
+
+ if (strlen(p) > FILENAME_MAX)
+ return false;
+
+ return true;
+}
+
+bool string_is_safe(const char *p) {
+ const char *t;
+
+ assert(p);
+
+ for (t = p; *t; t++) {
+ if (*p < ' ')
+ return false;
+
+ if (strchr("\\\"\'", *p))
+ return false;
+ }
+
+ return true;
+}
diff --git a/src/shared/util.h b/src/shared/util.h
index 61b88a8b2e..cbded08617 100644
--- a/src/shared/util.h
+++ b/src/shared/util.h
@@ -558,3 +558,6 @@ _malloc_ static inline void *memdup_multiply(const void *p, size_t a, size_t b)
return memdup(p, a * b);
}
+
+bool filename_is_safe(const char *p);
+bool string_is_safe(const char *p);