7 files changed, 63 insertions, 22 deletions

diff --git a/include/net/fib_rules.h b/include/net/fib_rules.h
index e5cfcfc7dd93..b473df5b9512 100644
--- a/include/net/fib_rules.h
+++ b/include/net/fib_rules.h
@@ -75,7 +75,8 @@ struct fib_rules_ops {
         int                     (*configure)(struct fib_rule *,
                                              struct sk_buff *,
                                              struct fib_rule_hdr *,
-                                             struct nlattr **);
+                                             struct nlattr **,
+                                             struct netlink_ext_ack *);
         int                     (*delete)(struct fib_rule *);
         int                     (*compare)(struct fib_rule *,
                                            struct fib_rule_hdr *,
diff --git a/net/core/fib_rules.c b/net/core/fib_rules.c
index 67801104e9a8..ebd9351b213a 100644
--- a/net/core/fib_rules.c
+++ b/net/core/fib_rules.c
@@ -469,14 +469,18 @@ static int fib_nl2rule(struct sk_buff *skb, struct nlmsghdr *nlh,
         if (frh->src_len)
                 if (!tb[FRA_SRC] ||
                     frh->src_len > (ops->addr_size * 8) ||
-                    nla_len(tb[FRA_SRC]) != ops->addr_size)
+                    nla_len(tb[FRA_SRC]) != ops->addr_size) {
+                        NL_SET_ERR_MSG(extack, "Invalid source address");
                         goto errout;
+        }
 
         if (frh->dst_len)
                 if (!tb[FRA_DST] ||
                     frh->dst_len > (ops->addr_size * 8) ||
-                    nla_len(tb[FRA_DST]) != ops->addr_size)
+                    nla_len(tb[FRA_DST]) != ops->addr_size) {
+                        NL_SET_ERR_MSG(extack, "Invalid dst address");
                         goto errout;
+        }
 
         nlrule = kzalloc(ops->rule_size, GFP_KERNEL);
         if (!nlrule) {
@@ -537,6 +541,7 @@ static int fib_nl2rule(struct sk_buff *skb, struct nlmsghdr *nlh,
                 nlrule->l3mdev = nla_get_u8(tb[FRA_L3MDEV]);
                 if (nlrule->l3mdev != 1)
 #endif
+                        NL_SET_ERR_MSG(extack, "Invalid l3mdev");
                         goto errout_free;
         }
 
@@ -554,31 +559,41 @@ static int fib_nl2rule(struct sk_buff *skb, struct nlmsghdr *nlh,
                 nlrule->suppress_ifgroup = -1;
 
         if (tb[FRA_GOTO]) {
-                if (nlrule->action != FR_ACT_GOTO)
+                if (nlrule->action != FR_ACT_GOTO) {
+                        NL_SET_ERR_MSG(extack, "Unexpected goto");
                         goto errout_free;
+                }
 
                 nlrule->target = nla_get_u32(tb[FRA_GOTO]);
                 /* Backward jumps are prohibited to avoid endless loops */
-                if (nlrule->target <= nlrule->pref)
+                if (nlrule->target <= nlrule->pref) {
+                        NL_SET_ERR_MSG(extack, "Backward goto not supported");
                         goto errout_free;
+                }
         } else if (nlrule->action == FR_ACT_GOTO) {
+                NL_SET_ERR_MSG(extack, "Missing goto target for action goto");
                 goto errout_free;
         }
 
-        if (nlrule->l3mdev && nlrule->table)
+        if (nlrule->l3mdev && nlrule->table) {
+                NL_SET_ERR_MSG(extack, "l3mdev and table are mutually exclusive");
                 goto errout_free;
+        }
 
         if (tb[FRA_UID_RANGE]) {
                 if (current_user_ns() != net->user_ns) {
                         err = -EPERM;
+                        NL_SET_ERR_MSG(extack, "No permission to set uid");
                         goto errout_free;
                 }
 
                 nlrule->uid_range = nla_get_kuid_range(tb);
 
                 if (!uid_range_set(&nlrule->uid_range) ||
-                    !uid_lte(nlrule->uid_range.start, nlrule->uid_range.end))
+                    !uid_lte(nlrule->uid_range.start, nlrule->uid_range.end)) {
+                        NL_SET_ERR_MSG(extack, "Invalid uid range");
                         goto errout_free;
+                }
         } else {
                 nlrule->uid_range = fib_kuid_range_unset;
         }
@@ -589,15 +604,19 @@ static int fib_nl2rule(struct sk_buff *skb, struct nlmsghdr *nlh,
         if (tb[FRA_SPORT_RANGE]) {
                 err = nla_get_port_range(tb[FRA_SPORT_RANGE],
                                          &nlrule->sport_range);
-                if (err)
+                if (err) {
+                        NL_SET_ERR_MSG(extack, "Invalid sport range");
                         goto errout_free;
+                }
         }
 
         if (tb[FRA_DPORT_RANGE]) {
                 err = nla_get_port_range(tb[FRA_DPORT_RANGE],
                                          &nlrule->dport_range);
-                if (err)
+                if (err) {
+                        NL_SET_ERR_MSG(extack, "Invalid dport range");
                         goto errout_free;
+                }
         }
 
         *rule = nlrule;
@@ -621,18 +640,23 @@ int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr *nlh,
         int err = -EINVAL, unresolved = 0;
         bool user_priority = false;
 
-        if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
+        if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) {
+                NL_SET_ERR_MSG(extack, "Invalid msg length");
                 goto errout;
+        }
 
         ops = lookup_rules_ops(net, frh->family);
         if (!ops) {
                 err = -EAFNOSUPPORT;
+                NL_SET_ERR_MSG(extack, "Rule family not supported");
                 goto errout;
         }
 
         err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy, extack);
-        if (err < 0)
+        if (err < 0) {
+                NL_SET_ERR_MSG(extack, "Error parsing msg");
                 goto errout;
+        }
 
         err = fib_nl2rule(skb, nlh, extack, ops, tb, &rule, &user_priority);
         if (err)
@@ -644,7 +668,7 @@ int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr *nlh,
                 goto errout_free;
         }
 
-        err = ops->configure(rule, skb, frh, tb);
+        err = ops->configure(rule, skb, frh, tb, extack);
         if (err < 0)
                 goto errout_free;
 
@@ -723,18 +747,23 @@ int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr *nlh,
         int err = -EINVAL;
         bool user_priority = false;
 
-        if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
+        if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) {
+                NL_SET_ERR_MSG(extack, "Invalid msg length");
                 goto errout;
+        }
 
         ops = lookup_rules_ops(net, frh->family);
         if (ops == NULL) {
                 err = -EAFNOSUPPORT;
+                NL_SET_ERR_MSG(extack, "Rule family not supported");
                 goto errout;
         }
 
         err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy, extack);
-        if (err < 0)
+        if (err < 0) {
+                NL_SET_ERR_MSG(extack, "Error parsing msg");
                 goto errout;
+        }
 
         err = fib_nl2rule(skb, nlh, extack, ops, tb, &nlrule, &user_priority);
         if (err)
diff --git a/net/decnet/dn_rules.c b/net/decnet/dn_rules.c
index c795c3f509c9..72236695db3d 100644
--- a/net/decnet/dn_rules.c
+++ b/net/decnet/dn_rules.c
@@ -121,13 +121,16 @@ static int dn_fib_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
 
 static int dn_fib_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
                                  struct fib_rule_hdr *frh,
-                                 struct nlattr **tb)
+                                 struct nlattr **tb,
+                                 struct netlink_ext_ack *extack)
 {
         int err = -EINVAL;
         struct dn_fib_rule *r = (struct dn_fib_rule *)rule;
 
-        if (frh->tos)
+        if (frh->tos) {
+                NL_SET_ERR_MSG(extack, "Invalid tos value");
                 goto  errout;
+        }
 
         if (rule->table == RT_TABLE_UNSPEC) {
                 if (rule->action == FR_ACT_TO_TBL) {
diff --git a/net/ipv4/fib_rules.c b/net/ipv4/fib_rules.c
index 737d11bc8838..f8eb78d042a4 100644
--- a/net/ipv4/fib_rules.c
+++ b/net/ipv4/fib_rules.c
@@ -213,14 +213,17 @@ static const struct nla_policy fib4_rule_policy[FRA_MAX+1] = {
 
 static int fib4_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
                                struct fib_rule_hdr *frh,
-                               struct nlattr **tb)
+                               struct nlattr **tb,
+                               struct netlink_ext_ack *extack)
 {
         struct net *net = sock_net(skb->sk);
         int err = -EINVAL;
         struct fib4_rule *rule4 = (struct fib4_rule *) rule;
 
-        if (frh->tos & ~IPTOS_TOS_MASK)
+        if (frh->tos & ~IPTOS_TOS_MASK) {
+                NL_SET_ERR_MSG(extack, "Invalid tos");
                 goto errout;
+        }
 
         /* split local/main if they are not already split */
         err = fib_unmerge(net);
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index 2fb4de3f7f66..38e092eafc97 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -201,7 +201,8 @@ static const struct nla_policy ipmr_rule_policy[FRA_MAX + 1] = {
 };
 
 static int ipmr_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
-                               struct fib_rule_hdr *frh, struct nlattr **tb)
+                               struct fib_rule_hdr *frh, struct nlattr **tb,
+                               struct netlink_ext_ack *extack)
 {
         return 0;
 }
diff --git a/net/ipv6/fib6_rules.c b/net/ipv6/fib6_rules.c
index df113c7b5fc8..6547fc6491a6 100644
--- a/net/ipv6/fib6_rules.c
+++ b/net/ipv6/fib6_rules.c
@@ -245,15 +245,18 @@ static const struct nla_policy fib6_rule_policy[FRA_MAX+1] = {
 
 static int fib6_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
                                struct fib_rule_hdr *frh,
-                               struct nlattr **tb)
+                               struct nlattr **tb,
+                               struct netlink_ext_ack *extack)
 {
         int err = -EINVAL;
         struct net *net = sock_net(skb->sk);
         struct fib6_rule *rule6 = (struct fib6_rule *) rule;
 
         if (rule->action == FR_ACT_TO_TBL && !rule->l3mdev) {
-                if (rule->table == RT6_TABLE_UNSPEC)
+                if (rule->table == RT6_TABLE_UNSPEC) {
+                        NL_SET_ERR_MSG(extack, "Invalid table");
                         goto errout;
+                }
 
                 if (fib6_new_table(net, rule->table) == NULL) {
                         err = -ENOBUFS;
diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c
index 298fd8b6ed17..20a419ee8000 100644
--- a/net/ipv6/ip6mr.c
+++ b/net/ipv6/ip6mr.c
@@ -180,7 +180,8 @@ static const struct nla_policy ip6mr_rule_policy[FRA_MAX + 1] = {
 };
 
 static int ip6mr_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
-                                struct fib_rule_hdr *frh, struct nlattr **tb)
+                                struct fib_rule_hdr *frh, struct nlattr **tb,
+                                struct netlink_ext_ack *extack)
 {
         return 0;
 }