From 268f983d2a9e093f1d432f4c530ed51f08f14870 Mon Sep 17 00:00:00 2001
From: Riccardo Schirone <rschiron@redhat.com>
Date: Mon, 4 Feb 2019 14:29:28 +0100
Subject: [PATCH] Allocate temporary strings to hold dbus paths on the heap
Paths are limited to BUS_PATH_SIZE_MAX but the maximum size is anyway too big
to be allocated on the stack, so let's switch to the heap where there is a
clear way to understand if the allocation fails.
(cherry-picked from commit f519a19bcd5afe674a9b8fc462cd77d8bad403c1)
Related: #1678641
---
src/libsystemd/sd-bus/bus-objects.c | 68 +++++++++++++++++++++++------
1 file changed, 54 insertions(+), 14 deletions(-)
diff --git a/src/libsystemd/sd-bus/bus-objects.c b/src/libsystemd/sd-bus/bus-objects.c
index a18ff88b0..53bf0fd62 100644
--- a/src/libsystemd/sd-bus/bus-objects.c
+++ b/src/libsystemd/sd-bus/bus-objects.c
@@ -1134,7 +1134,8 @@ static int object_manager_serialize_path_and_fallbacks(
const char *path,
sd_bus_error *error) {
- char *prefix;
+ _cleanup_free_ char *prefix = NULL;
+ size_t pl;
int r;
assert(bus);
@@ -1150,7 +1151,12 @@ static int object_manager_serialize_path_and_fallbacks(
return 0;
/* Second, add fallback vtables registered for any of the prefixes */
- prefix = alloca(strlen(path) + 1);
+ pl = strlen(path);
+ assert(pl <= BUS_PATH_SIZE_MAX);
+ prefix = new(char, pl + 1);
+ if (!prefix)
+ return -ENOMEM;
+
OBJECT_PATH_FOREACH_PREFIX(prefix, path) {
r = object_manager_serialize_path(bus, reply, prefix, path, true, error);
if (r < 0)
@@ -1346,6 +1352,7 @@ static int object_find_and_run(
}
int bus_process_object(sd_bus *bus, sd_bus_message *m) {
+ _cleanup_free_ char *prefix = NULL;
int r;
size_t pl;
bool found_object = false;
@@ -1370,9 +1377,12 @@ int bus_process_object(sd_bus *bus, sd_bus_message *m) {
assert(m->member);
pl = strlen(m->path);
- do {
- char prefix[pl+1];
+ assert(pl <= BUS_PATH_SIZE_MAX);
+ prefix = new(char, pl + 1);
+ if (!prefix)
+ return -ENOMEM;
+ do {
bus->nodes_modified = false;
r = object_find_and_run(bus, m, m->path, false, &found_object);
@@ -1499,9 +1509,15 @@ static int bus_find_parent_object_manager(sd_bus *bus, struct node **out, const
n = hashmap_get(bus->nodes, path);
if (!n) {
- char *prefix;
+ _cleanup_free_ char *prefix = NULL;
+ size_t pl;
+
+ pl = strlen(path);
+ assert(pl <= BUS_PATH_SIZE_MAX);
+ prefix = new(char, pl + 1);
+ if (!prefix)
+ return -ENOMEM;
- prefix = alloca(strlen(path) + 1);
OBJECT_PATH_FOREACH_PREFIX(prefix, path) {
n = hashmap_get(bus->nodes, prefix);
if (n)
@@ -2090,8 +2106,9 @@ _public_ int sd_bus_emit_properties_changed_strv(
const char *interface,
char **names) {
+ _cleanup_free_ char *prefix = NULL;
bool found_interface = false;
- char *prefix;
+ size_t pl;
int r;
assert_return(bus, -EINVAL);
@@ -2112,6 +2129,12 @@ _public_ int sd_bus_emit_properties_changed_strv(
BUS_DONT_DESTROY(bus);
+ pl = strlen(path);
+ assert(pl <= BUS_PATH_SIZE_MAX);
+ prefix = new(char, pl + 1);
+ if (!prefix)
+ return -ENOMEM;
+
do {
bus->nodes_modified = false;
@@ -2121,7 +2144,6 @@ _public_ int sd_bus_emit_properties_changed_strv(
if (bus->nodes_modified)
continue;
- prefix = alloca(strlen(path) + 1);
OBJECT_PATH_FOREACH_PREFIX(prefix, path) {
r = emit_properties_changed_on_interface(bus, prefix, path, interface, true, &found_interface, names);
if (r != 0)
@@ -2253,7 +2275,8 @@ static int object_added_append_all_prefix(
static int object_added_append_all(sd_bus *bus, sd_bus_message *m, const char *path) {
_cleanup_set_free_ Set *s = NULL;
- char *prefix;
+ _cleanup_free_ char *prefix = NULL;
+ size_t pl;
int r;
assert(bus);
@@ -2298,7 +2321,12 @@ static int object_added_append_all(sd_bus *bus, sd_bus_message *m, const char *p
if (bus->nodes_modified)
return 0;
- prefix = alloca(strlen(path) + 1);
+ pl = strlen(path);
+ assert(pl <= BUS_PATH_SIZE_MAX);
+ prefix = new(char, pl + 1);
+ if (!prefix)
+ return -ENOMEM;
+
OBJECT_PATH_FOREACH_PREFIX(prefix, path) {
r = object_added_append_all_prefix(bus, m, s, prefix, path, true);
if (r < 0)
@@ -2437,7 +2465,8 @@ static int object_removed_append_all_prefix(
static int object_removed_append_all(sd_bus *bus, sd_bus_message *m, const char *path) {
_cleanup_set_free_ Set *s = NULL;
- char *prefix;
+ _cleanup_free_ char *prefix = NULL;
+ size_t pl;
int r;
assert(bus);
@@ -2469,7 +2498,12 @@ static int object_removed_append_all(sd_bus *bus, sd_bus_message *m, const char
if (bus->nodes_modified)
return 0;
- prefix = alloca(strlen(path) + 1);
+ pl = strlen(path);
+ assert(pl <= BUS_PATH_SIZE_MAX);
+ prefix = new(char, pl + 1);
+ if (!prefix)
+ return -ENOMEM;
+
OBJECT_PATH_FOREACH_PREFIX(prefix, path) {
r = object_removed_append_all_prefix(bus, m, s, prefix, path, true);
if (r < 0)
@@ -2619,7 +2653,8 @@ static int interfaces_added_append_one(
const char *path,
const char *interface) {
- char *prefix;
+ _cleanup_free_ char *prefix = NULL;
+ size_t pl;
int r;
assert(bus);
@@ -2633,7 +2668,12 @@ static int interfaces_added_append_one(
if (bus->nodes_modified)
return 0;
- prefix = alloca(strlen(path) + 1);
+ pl = strlen(path);
+ assert(pl <= BUS_PATH_SIZE_MAX);
+ prefix = new(char, pl + 1);
+ if (!prefix)
+ return -ENOMEM;
+
OBJECT_PATH_FOREACH_PREFIX(prefix, path) {
r = interfaces_added_append_one_prefix(bus, m, prefix, path, interface, true);
if (r != 0)