[NETLINK]: Make use of NLA_STRING/NLA_NUL_STRING attribute validation

Converts existing NLA_STRING attributes to use the new
validation features, saving a couple of temporary buffers.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

9 files changed, 17 insertions, 26 deletions

diff --git a/net/core/fib_rules.c b/net/core/fib_rules.c
index 7b2e9bb1a605..a99d87d82b7f 100644
--- a/net/core/fib_rules.c
+++ b/net/core/fib_rules.c
@@ -161,9 +161,6 @@ int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
         if (err < 0)
                 goto errout;
 
-        if (tb[FRA_IFNAME] && nla_len(tb[FRA_IFNAME]) > IFNAMSIZ)
-                goto errout;
-
         rule = kzalloc(ops->rule_size, GFP_KERNEL);
         if (rule == NULL) {
                 err = -ENOMEM;
@@ -177,10 +174,7 @@ int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
                 struct net_device *dev;
 
                 rule->ifindex = -1;
-                if (nla_strlcpy(rule->ifname, tb[FRA_IFNAME],
-                                IFNAMSIZ) >= IFNAMSIZ)
-                        goto errout_free;
-
+                nla_strlcpy(rule->ifname, tb[FRA_IFNAME], IFNAMSIZ);
                 dev = __dev_get_by_name(rule->ifname);
                 if (dev)
                         rule->ifindex = dev->ifindex;
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 8f225499e32e..0ebcf8488e99 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -371,8 +371,8 @@ static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
 }
 
 static struct nla_policy ifla_policy[IFLA_MAX+1] __read_mostly = {
-        [IFLA_IFNAME]           = { .type = NLA_STRING },
-        [IFLA_MAP]              = { .minlen = sizeof(struct rtnl_link_ifmap) },
+        [IFLA_IFNAME]           = { .type = NLA_STRING, .len = IFNAMSIZ-1 },
+        [IFLA_MAP]              = { .len = sizeof(struct rtnl_link_ifmap) },
         [IFLA_MTU]              = { .type = NLA_U32 },
         [IFLA_TXQLEN]           = { .type = NLA_U32 },
         [IFLA_WEIGHT]           = { .type = NLA_U32 },
@@ -392,9 +392,8 @@ static int rtnl_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
         if (err < 0)
                 goto errout;
 
-        if (tb[IFLA_IFNAME] &&
-            nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ) >= IFNAMSIZ)
-                return -EINVAL;
+        if (tb[IFLA_IFNAME])
+                nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
 
         err = -EINVAL;
         ifm = nlmsg_data(nlh);
diff --git a/net/decnet/dn_rules.c b/net/decnet/dn_rules.c
index 63ad63dfd252..3e0c882c90bf 100644
--- a/net/decnet/dn_rules.c
+++ b/net/decnet/dn_rules.c
@@ -112,7 +112,7 @@ errout:
 }
 
 static struct nla_policy dn_fib_rule_policy[FRA_MAX+1] __read_mostly = {
-        [FRA_IFNAME]    = { .type = NLA_STRING },
+        [FRA_IFNAME]    = { .type = NLA_STRING, .len = IFNAMSIZ - 1 },
         [FRA_PRIORITY]  = { .type = NLA_U32 },
         [FRA_SRC]       = { .type = NLA_U16 },
         [FRA_DST]       = { .type = NLA_U16 },
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 0487677729cf..8e8d1f17d77a 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -85,7 +85,7 @@ static struct nla_policy ifa_ipv4_policy[IFA_MAX+1] __read_mostly = {
         [IFA_ADDRESS]           = { .type = NLA_U32 },
         [IFA_BROADCAST]         = { .type = NLA_U32 },
         [IFA_ANYCAST]           = { .type = NLA_U32 },
-        [IFA_LABEL]             = { .type = NLA_STRING },
+        [IFA_LABEL]             = { .type = NLA_STRING, .len = IFNAMSIZ - 1 },
 };
 
 static void rtmsg_ifa(int event, struct in_ifaddr *, struct nlmsghdr *, u32);
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index d0abeab16e66..cfb527c060e4 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -462,7 +462,7 @@ struct nla_policy rtm_ipv4_policy[RTA_MAX+1] __read_mostly = {
         [RTA_PRIORITY]          = { .type = NLA_U32 },
         [RTA_PREFSRC]           = { .type = NLA_U32 },
         [RTA_METRICS]           = { .type = NLA_NESTED },
-        [RTA_MULTIPATH]         = { .minlen = sizeof(struct rtnexthop) },
+        [RTA_MULTIPATH]         = { .len = sizeof(struct rtnexthop) },
         [RTA_PROTOINFO]         = { .type = NLA_U32 },
         [RTA_FLOW]              = { .type = NLA_U32 },
         [RTA_MP_ALGO]           = { .type = NLA_U32 },
diff --git a/net/ipv4/fib_rules.c b/net/ipv4/fib_rules.c
index 280f424ca9c9..52b2adae4f22 100644
--- a/net/ipv4/fib_rules.c
+++ b/net/ipv4/fib_rules.c
@@ -179,7 +179,7 @@ static struct fib_table *fib_empty_table(void)
 }
 
 static struct nla_policy fib4_rule_policy[FRA_MAX+1] __read_mostly = {
-        [FRA_IFNAME]    = { .type = NLA_STRING },
+        [FRA_IFNAME]    = { .type = NLA_STRING, .len = IFNAMSIZ - 1 },
         [FRA_PRIORITY]  = { .type = NLA_U32 },
         [FRA_SRC]       = { .type = NLA_U32 },
         [FRA_DST]       = { .type = NLA_U32 },
diff --git a/net/ipv6/fib6_rules.c b/net/ipv6/fib6_rules.c
index 2fbc71d90187..34f5bfaddfc2 100644
--- a/net/ipv6/fib6_rules.c
+++ b/net/ipv6/fib6_rules.c
@@ -137,10 +137,10 @@ static int fib6_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
 }
 
 static struct nla_policy fib6_rule_policy[FRA_MAX+1] __read_mostly = {
-        [FRA_IFNAME]    = { .type = NLA_STRING },
+        [FRA_IFNAME]    = { .type = NLA_STRING, .len = IFNAMSIZ - 1 },
         [FRA_PRIORITY]  = { .type = NLA_U32 },
-        [FRA_SRC]       = { .minlen = sizeof(struct in6_addr) },
-        [FRA_DST]       = { .minlen = sizeof(struct in6_addr) },
+        [FRA_SRC]       = { .len = sizeof(struct in6_addr) },
+        [FRA_DST]       = { .len = sizeof(struct in6_addr) },
         [FRA_FWMARK]    = { .type = NLA_U32 },
         [FRA_FWMASK]    = { .type = NLA_U32 },
         [FRA_TABLE]     = { .type = NLA_U32 },
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index ba1b3d11865e..75f4bb9611ce 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1865,7 +1865,7 @@ void rt6_mtu_change(struct net_device *dev, unsigned mtu)
 }
 
 static struct nla_policy rtm_ipv6_policy[RTA_MAX+1] __read_mostly = {
-        [RTA_GATEWAY]           = { .minlen = sizeof(struct in6_addr) },
+        [RTA_GATEWAY]           = { .len = sizeof(struct in6_addr) },
         [RTA_OIF]               = { .type = NLA_U32 },
         [RTA_IIF]               = { .type = NLA_U32 },
         [RTA_PRIORITY]          = { .type = NLA_U32 },
diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c
index d32599116c56..3ac942cdb677 100644
--- a/net/netlink/genetlink.c
+++ b/net/netlink/genetlink.c
@@ -455,7 +455,8 @@ static struct sk_buff *ctrl_build_msg(struct genl_family *family, u32 pid,
 
 static struct nla_policy ctrl_policy[CTRL_ATTR_MAX+1] __read_mostly = {
         [CTRL_ATTR_FAMILY_ID]   = { .type = NLA_U16 },
-        [CTRL_ATTR_FAMILY_NAME] = { .type = NLA_STRING },
+        [CTRL_ATTR_FAMILY_NAME] = { .type = NLA_NUL_STRING,
+                                    .len = GENL_NAMSIZ - 1 },
 };
 
 static int ctrl_getfamily(struct sk_buff *skb, struct genl_info *info)
@@ -470,12 +471,9 @@ static int ctrl_getfamily(struct sk_buff *skb, struct genl_info *info)
         }
 
         if (info->attrs[CTRL_ATTR_FAMILY_NAME]) {
-                char name[GENL_NAMSIZ];
-
-                if (nla_strlcpy(name, info->attrs[CTRL_ATTR_FAMILY_NAME],
-                                GENL_NAMSIZ) >= GENL_NAMSIZ)
-                        goto errout;
+                char *name;
 
+                name = nla_data(info->attrs[CTRL_ATTR_FAMILY_NAME]);
                 res = genl_family_find_byname(name);
         }