1 files changed, 42 insertions, 13 deletions

diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c
index 25eeb6d2a75a..efccd1ac9a66 100644
--- a/net/netlink/genetlink.c
+++ b/net/netlink/genetlink.c
@@ -362,11 +362,11 @@ int genl_register_family(struct genl_family *family)
 	} else
 		family->attrbuf = NULL;
 
-	family->id = idr_alloc(&genl_fam_idr, family,
-			       start, end + 1, GFP_KERNEL);
+	family->id = idr_alloc_cyclic(&genl_fam_idr, family,
+				      start, end + 1, GFP_KERNEL);
 	if (family->id < 0) {
 		err = family->id;
-		goto errout_locked;
+		goto errout_free;
 	}
 
 	err = genl_validate_assign_mc_groups(family);
@@ -385,6 +385,7 @@ int genl_register_family(struct genl_family *family)
 
 errout_remove:
 	idr_remove(&genl_fam_idr, family->id);
+errout_free:
 	kfree(family->attrbuf);
 errout_locked:
 	genl_unlock_all();
@@ -535,6 +536,28 @@ static int genl_family_rcv_msg(const struct genl_family *family,
 		if (ops->dumpit == NULL)
 			return -EOPNOTSUPP;
 
+		if (!(ops->validate & GENL_DONT_VALIDATE_DUMP)) {
+			int hdrlen = GENL_HDRLEN + family->hdrsize;
+
+			if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
+				return -EINVAL;
+
+			if (family->maxattr) {
+				unsigned int validate = NL_VALIDATE_STRICT;
+
+				if (ops->validate &
+				    GENL_DONT_VALIDATE_DUMP_STRICT)
+					validate = NL_VALIDATE_LIBERAL;
+				rc = __nla_validate(nlmsg_attrdata(nlh, hdrlen),
+						    nlmsg_attrlen(nlh, hdrlen),
+						    family->maxattr,
+						    family->policy,
+						    validate, extack);
+				if (rc)
+					return rc;
+			}
+		}
+
 		if (!family->parallel_ops) {
 			struct netlink_dump_control c = {
 				.module = family->module,
@@ -576,8 +599,13 @@ static int genl_family_rcv_msg(const struct genl_family *family,
 		attrbuf = family->attrbuf;
 
 	if (attrbuf) {
-		err = nlmsg_parse(nlh, hdrlen, attrbuf, family->maxattr,
-				  ops->policy, extack);
+		enum netlink_validation validate = NL_VALIDATE_STRICT;
+
+		if (ops->validate & GENL_DONT_VALIDATE_STRICT)
+			validate = NL_VALIDATE_LIBERAL;
+
+		err = __nlmsg_parse(nlh, hdrlen, attrbuf, family->maxattr,
+				    family->policy, validate, extack);
 		if (err < 0)
 			goto out;
 	}
@@ -664,7 +692,7 @@ static int ctrl_fill_info(const struct genl_family *family, u32 portid, u32 seq,
 		struct nlattr *nla_ops;
 		int i;
 
-		nla_ops = nla_nest_start(skb, CTRL_ATTR_OPS);
+		nla_ops = nla_nest_start_noflag(skb, CTRL_ATTR_OPS);
 		if (nla_ops == NULL)
 			goto nla_put_failure;
 
@@ -677,10 +705,10 @@ static int ctrl_fill_info(const struct genl_family *family, u32 portid, u32 seq,
 				op_flags |= GENL_CMD_CAP_DUMP;
 			if (ops->doit)
 				op_flags |= GENL_CMD_CAP_DO;
-			if (ops->policy)
+			if (family->policy)
 				op_flags |= GENL_CMD_CAP_HASPOL;
 
-			nest = nla_nest_start(skb, i + 1);
+			nest = nla_nest_start_noflag(skb, i + 1);
 			if (nest == NULL)
 				goto nla_put_failure;
 
@@ -698,7 +726,7 @@ static int ctrl_fill_info(const struct genl_family *family, u32 portid, u32 seq,
 		struct nlattr *nla_grps;
 		int i;
 
-		nla_grps = nla_nest_start(skb, CTRL_ATTR_MCAST_GROUPS);
+		nla_grps = nla_nest_start_noflag(skb, CTRL_ATTR_MCAST_GROUPS);
 		if (nla_grps == NULL)
 			goto nla_put_failure;
 
@@ -708,7 +736,7 @@ static int ctrl_fill_info(const struct genl_family *family, u32 portid, u32 seq,
 
 			grp = &family->mcgrps[i];
 
-			nest = nla_nest_start(skb, i + 1);
+			nest = nla_nest_start_noflag(skb, i + 1);
 			if (nest == NULL)
 				goto nla_put_failure;
 
@@ -748,11 +776,11 @@ static int ctrl_fill_mcgrp_info(const struct genl_family *family,
 	    nla_put_u16(skb, CTRL_ATTR_FAMILY_ID, family->id))
 		goto nla_put_failure;
 
-	nla_grps = nla_nest_start(skb, CTRL_ATTR_MCAST_GROUPS);
+	nla_grps = nla_nest_start_noflag(skb, CTRL_ATTR_MCAST_GROUPS);
 	if (nla_grps == NULL)
 		goto nla_put_failure;
 
-	nest = nla_nest_start(skb, 1);
+	nest = nla_nest_start_noflag(skb, 1);
 	if (nest == NULL)
 		goto nla_put_failure;
 
@@ -937,9 +965,9 @@ static int genl_ctrl_event(int event, const struct genl_family *family,
 static const struct genl_ops genl_ctrl_ops[] = {
 	{
 		.cmd		= CTRL_CMD_GETFAMILY,
+		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 		.doit		= ctrl_getfamily,
 		.dumpit		= ctrl_dumpfamily,
-		.policy		= ctrl_policy,
 	},
 };
 
@@ -957,6 +985,7 @@ static struct genl_family genl_ctrl __ro_after_init = {
 	.name = "nlctrl",
 	.version = 0x2,
 	.maxattr = CTRL_ATTR_MAX,
+	.policy = ctrl_policy,
 	.netnsok = true,
 };