systemd: Fix uninitialised memory issue in veth setup

This caused containers to randomly fail, in particular if the machine
name was 8 characters.
This commit is contained in:
Eelco Dolstra 2014-08-15 04:07:45 +02:00
parent a323d146b7
commit 97d6afafaa

View file

@ -1074,6 +1074,123 @@ index b087a8b..967ab67 100644
test_catalog_file_lang();
diff --git a/src/libsystemd/sd-rtnl/rtnl-message.c b/src/libsystemd/sd-rtnl/rtnl-message.c
index 84a8ffa..e79b318 100644
--- a/src/libsystemd/sd-rtnl/rtnl-message.c
+++ b/src/libsystemd/sd-rtnl/rtnl-message.c
@@ -335,24 +335,28 @@ int sd_rtnl_message_link_get_flags(sd_rtnl_message *m, unsigned *flags) {
/* If successful the updated message will be correctly aligned, if
unsuccessful the old message is untouched. */
static int add_rtattr(sd_rtnl_message *m, unsigned short type, const void *data, size_t data_length) {
- uint32_t rta_length, message_length;
+ uint32_t rta_length;
+ size_t message_length, padding_length;
struct nlmsghdr *new_hdr;
struct rtattr *rta;
char *padding;
unsigned i;
+ int offset;
assert(m);
assert(m->hdr);
assert(!m->sealed);
assert(NLMSG_ALIGN(m->hdr->nlmsg_len) == m->hdr->nlmsg_len);
- assert(!data || data_length > 0);
- assert(data || m->n_containers < RTNL_CONTAINER_DEPTH);
+ assert(!data || data_length);
+
+ /* get offset of the new attribute */
+ offset = m->hdr->nlmsg_len;
/* get the size of the new rta attribute (with padding at the end) */
rta_length = RTA_LENGTH(data_length);
/* get the new message size (with padding at the end) */
- message_length = m->hdr->nlmsg_len + RTA_ALIGN(rta_length);
+ message_length = offset + RTA_ALIGN(rta_length);
/* realloc to fit the new attribute */
new_hdr = realloc(m->hdr, message_length);
@@ -361,32 +365,35 @@ static int add_rtattr(sd_rtnl_message *m, unsigned short type, const void *data,
m->hdr = new_hdr;
/* get pointer to the attribute we are about to add */
- rta = (struct rtattr *) ((uint8_t *) m->hdr + m->hdr->nlmsg_len);
+ rta = (struct rtattr *) ((uint8_t *) m->hdr + offset);
/* if we are inside containers, extend them */
for (i = 0; i < m->n_containers; i++)
- GET_CONTAINER(m, i)->rta_len += message_length - m->hdr->nlmsg_len;
+ GET_CONTAINER(m, i)->rta_len += message_length - offset;
/* fill in the attribute */
rta->rta_type = type;
rta->rta_len = rta_length;
- if (!data) {
- /* this is the start of a new container */
- m->container_offsets[m->n_containers ++] = m->hdr->nlmsg_len;
- } else {
+ if (data)
/* we don't deal with the case where the user lies about the type
* and gives us too little data (so don't do that)
- */
+ */
padding = mempcpy(RTA_DATA(rta), data, data_length);
- /* make sure also the padding at the end of the message is initialized */
- memzero(padding,
- (uint8_t *) m->hdr + message_length - (uint8_t *) padding);
+ else {
+ /* if no data was passed, make sure we still initialize the padding
+ note that we can have data_length > 0 (used by some containers) */
+ padding = RTA_DATA(rta);
+ data_length = 0;
}
+ /* make sure also the padding at the end of the message is initialized */
+ padding_length = (uint8_t*)m->hdr + message_length - (uint8_t*)padding;
+ memzero(padding, padding_length);
+
/* update message size */
m->hdr->nlmsg_len = message_length;
- return 0;
+ return offset;
}
int sd_rtnl_message_append_string(sd_rtnl_message *m, unsigned short type, const char *data) {
@@ -761,22 +768,29 @@ int sd_rtnl_message_open_container(sd_rtnl_message *m, unsigned short type) {
assert_return(m, -EINVAL);
assert_return(!m->sealed, -EPERM);
+ assert_return(m->n_containers < RTNL_CONTAINER_DEPTH, -ERANGE);
sd_rtnl_message_get_type(m, &rtm_type);
+ int r = -ENOTSUP;
+
if (rtnl_message_type_is_link(rtm_type)) {
if ((type == IFLA_LINKINFO && m->n_containers == 0) ||
(type == IFLA_INFO_DATA && m->n_containers == 1 &&
GET_CONTAINER(m, 0)->rta_type == IFLA_LINKINFO))
- return add_rtattr(m, type, NULL, 0);
+ r = add_rtattr(m, type, NULL, 0);
else if (type == VETH_INFO_PEER && m->n_containers == 2 &&
GET_CONTAINER(m, 1)->rta_type == IFLA_INFO_DATA &&
GET_CONTAINER(m, 0)->rta_type == IFLA_LINKINFO)
- return add_rtattr(m, type, NULL, sizeof(struct ifinfomsg));
+ r= add_rtattr(m, type, NULL, sizeof(struct ifinfomsg));
}
- return -ENOTSUP;
+ if (r < 0) return r;
+
+ m->container_offsets[m->n_containers ++] = r;
+
+ return 0;
}
int sd_rtnl_message_close_container(sd_rtnl_message *m) {
diff --git a/src/libudev/libudev-monitor.c b/src/libudev/libudev-monitor.c
index ba1b04d..85b1e40 100644
--- a/src/libudev/libudev-monitor.c