tipc: fix potential null pointer dereferences in some compat functions

Before calling the nla_parse_nested function, make sure the pointer to the
attribute is not null. This patch fixes several potential null pointer
dereference vulnerabilities in the tipc netlink functions.

Signed-off-by: Baozeng Ding <sploving1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/tipc/netlink_compat.c b/net/tipc/netlink_compat.c
index 4dfc5c1..f795b1d 100644 (file)
--- a/net/tipc/netlink_compat.c
+++ b/net/tipc/netlink_compat.c
@@ -346,9 +346,15 @@ static int tipc_nl_compat_bearer_dump(struct tipc_nl_compat_msg *msg,
                                      struct nlattr **attrs)
 {
        struct nlattr *bearer[TIPC_NLA_BEARER_MAX + 1];
+       int err;
+
+       if (!attrs[TIPC_NLA_BEARER])
+               return -EINVAL;
 
-       nla_parse_nested(bearer, TIPC_NLA_BEARER_MAX, attrs[TIPC_NLA_BEARER],
-                        NULL);
+       err = nla_parse_nested(bearer, TIPC_NLA_BEARER_MAX,
+                              attrs[TIPC_NLA_BEARER], NULL);
+       if (err)
+               return err;
 
        return tipc_add_tlv(msg->rep, TIPC_TLV_BEARER_NAME,
                            nla_data(bearer[TIPC_NLA_BEARER_NAME]),
@@ -460,14 +466,31 @@ static int tipc_nl_compat_link_stat_dump(struct tipc_nl_compat_msg *msg,
        struct nlattr *link[TIPC_NLA_LINK_MAX + 1];
        struct nlattr *prop[TIPC_NLA_PROP_MAX + 1];
        struct nlattr *stats[TIPC_NLA_STATS_MAX + 1];
+       int err;
 
-       nla_parse_nested(link, TIPC_NLA_LINK_MAX, attrs[TIPC_NLA_LINK], NULL);
+       if (!attrs[TIPC_NLA_LINK])
+               return -EINVAL;
 
-       nla_parse_nested(prop, TIPC_NLA_PROP_MAX, link[TIPC_NLA_LINK_PROP],
-                        NULL);
+       err = nla_parse_nested(link, TIPC_NLA_LINK_MAX, attrs[TIPC_NLA_LINK],
+                              NULL);
+       if (err)
+               return err;
+
+       if (!link[TIPC_NLA_LINK_PROP])
+               return -EINVAL;
 
-       nla_parse_nested(stats, TIPC_NLA_STATS_MAX, link[TIPC_NLA_LINK_STATS],
-                        NULL);
+       err = nla_parse_nested(prop, TIPC_NLA_PROP_MAX,
+                              link[TIPC_NLA_LINK_PROP], NULL);
+       if (err)
+               return err;
+
+       if (!link[TIPC_NLA_LINK_STATS])
+               return -EINVAL;
+
+       err = nla_parse_nested(stats, TIPC_NLA_STATS_MAX,
+                              link[TIPC_NLA_LINK_STATS], NULL);
+       if (err)
+               return err;
 
        name = (char *)TLV_DATA(msg->req);
        if (strcmp(name, nla_data(link[TIPC_NLA_LINK_NAME])) != 0)
@@ -569,8 +592,15 @@ static int tipc_nl_compat_link_dump(struct tipc_nl_compat_msg *msg,
 {
        struct nlattr *link[TIPC_NLA_LINK_MAX + 1];
        struct tipc_link_info link_info;
+       int err;
 
-       nla_parse_nested(link, TIPC_NLA_LINK_MAX, attrs[TIPC_NLA_LINK], NULL);
+       if (!attrs[TIPC_NLA_LINK])
+               return -EINVAL;
+
+       err = nla_parse_nested(link, TIPC_NLA_LINK_MAX, attrs[TIPC_NLA_LINK],
+                              NULL);
+       if (err)
+               return err;
 
        link_info.dest = nla_get_flag(link[TIPC_NLA_LINK_DEST]);
        link_info.up = htonl(nla_get_flag(link[TIPC_NLA_LINK_UP]));
@@ -758,12 +788,23 @@ static int tipc_nl_compat_name_table_dump(struct tipc_nl_compat_msg *msg,
        u32 node, depth, type, lowbound, upbound;
        static const char * const scope_str[] = {"", " zone", " cluster",
                                                 " node"};
+       int err;
 
-       nla_parse_nested(nt, TIPC_NLA_NAME_TABLE_MAX,
-                        attrs[TIPC_NLA_NAME_TABLE], NULL);
+       if (!attrs[TIPC_NLA_NAME_TABLE])
+               return -EINVAL;
 
-       nla_parse_nested(publ, TIPC_NLA_PUBL_MAX, nt[TIPC_NLA_NAME_TABLE_PUBL],
-                        NULL);
+       err = nla_parse_nested(nt, TIPC_NLA_NAME_TABLE_MAX,
+                              attrs[TIPC_NLA_NAME_TABLE], NULL);
+       if (err)
+               return err;
+
+       if (!nt[TIPC_NLA_NAME_TABLE_PUBL])
+               return -EINVAL;
+
+       err = nla_parse_nested(publ, TIPC_NLA_PUBL_MAX,
+                              nt[TIPC_NLA_NAME_TABLE_PUBL], NULL);
+       if (err)
+               return err;
 
        ntq = (struct tipc_name_table_query *)TLV_DATA(msg->req);
 
@@ -815,8 +856,15 @@ static int __tipc_nl_compat_publ_dump(struct tipc_nl_compat_msg *msg,
 {
        u32 type, lower, upper;
        struct nlattr *publ[TIPC_NLA_PUBL_MAX + 1];
+       int err;
 
-       nla_parse_nested(publ, TIPC_NLA_PUBL_MAX, attrs[TIPC_NLA_PUBL], NULL);
+       if (!attrs[TIPC_NLA_PUBL])
+               return -EINVAL;
+
+       err = nla_parse_nested(publ, TIPC_NLA_PUBL_MAX, attrs[TIPC_NLA_PUBL],
+                              NULL);
+       if (err)
+               return err;
 
        type = nla_get_u32(publ[TIPC_NLA_PUBL_TYPE]);
        lower = nla_get_u32(publ[TIPC_NLA_PUBL_LOWER]);
@@ -876,7 +924,13 @@ static int tipc_nl_compat_sk_dump(struct tipc_nl_compat_msg *msg,
        u32 sock_ref;
        struct nlattr *sock[TIPC_NLA_SOCK_MAX + 1];
 
-       nla_parse_nested(sock, TIPC_NLA_SOCK_MAX, attrs[TIPC_NLA_SOCK], NULL);
+       if (!attrs[TIPC_NLA_SOCK])
+               return -EINVAL;
+
+       err = nla_parse_nested(sock, TIPC_NLA_SOCK_MAX, attrs[TIPC_NLA_SOCK],
+                              NULL);
+       if (err)
+               return err;
 
        sock_ref = nla_get_u32(sock[TIPC_NLA_SOCK_REF]);
        tipc_tlv_sprintf(msg->rep, "%u:", sock_ref);
@@ -917,9 +971,15 @@ static int tipc_nl_compat_media_dump(struct tipc_nl_compat_msg *msg,
                                     struct nlattr **attrs)
 {
        struct nlattr *media[TIPC_NLA_MEDIA_MAX + 1];
+       int err;
+
+       if (!attrs[TIPC_NLA_MEDIA])
+               return -EINVAL;
 
-       nla_parse_nested(media, TIPC_NLA_MEDIA_MAX, attrs[TIPC_NLA_MEDIA],
-                        NULL);
+       err = nla_parse_nested(media, TIPC_NLA_MEDIA_MAX, attrs[TIPC_NLA_MEDIA],
+                              NULL);
+       if (err)
+               return err;
 
        return tipc_add_tlv(msg->rep, TIPC_TLV_MEDIA_NAME,
                            nla_data(media[TIPC_NLA_MEDIA_NAME]),
@@ -931,8 +991,15 @@ static int tipc_nl_compat_node_dump(struct tipc_nl_compat_msg *msg,
 {
        struct tipc_node_info node_info;
        struct nlattr *node[TIPC_NLA_NODE_MAX + 1];
+       int err;
 
-       nla_parse_nested(node, TIPC_NLA_NODE_MAX, attrs[TIPC_NLA_NODE], NULL);
+       if (!attrs[TIPC_NLA_NODE])
+               return -EINVAL;
+
+       err = nla_parse_nested(node, TIPC_NLA_NODE_MAX, attrs[TIPC_NLA_NODE],
+                              NULL);
+       if (err)
+               return err;
 
        node_info.addr = htonl(nla_get_u32(node[TIPC_NLA_NODE_ADDR]));
        node_info.up = htonl(nla_get_flag(node[TIPC_NLA_NODE_UP]));
@@ -971,8 +1038,16 @@ static int tipc_nl_compat_net_dump(struct tipc_nl_compat_msg *msg,
 {
        __be32 id;
        struct nlattr *net[TIPC_NLA_NET_MAX + 1];
+       int err;
+
+       if (!attrs[TIPC_NLA_NET])
+               return -EINVAL;
+
+       err = nla_parse_nested(net, TIPC_NLA_NET_MAX, attrs[TIPC_NLA_NET],
+                              NULL);
+       if (err)
+               return err;
 
-       nla_parse_nested(net, TIPC_NLA_NET_MAX, attrs[TIPC_NLA_NET], NULL);
        id = htonl(nla_get_u32(net[TIPC_NLA_NET_ID]));
 
        return tipc_add_tlv(msg->rep, TIPC_TLV_UNSIGNED, &id, sizeof(id));