diff options
| author | Michal Kubecek <mkubecek@suse.cz> | 2019-05-02 16:15:10 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-05-04 01:27:11 -0400 |
| commit | b424e432e770d6dd572765459d5b6a96a19c5286 (patch) | |
| tree | f2aad0917c7a2e619bca6eefa82eb6b3355fb537 | |
| parent | d54a16b20157ce300298eb4a1169bf9acfda3d08 (diff) | |
netlink: add validation of NLA_F_NESTED flag
Add new validation flag NL_VALIDATE_NESTED which adds three consistency
checks of NLA_F_NESTED_FLAG:
- the flag is set on attributes with NLA_NESTED{,_ARRAY} policy
- the flag is not set on attributes with other policies except NLA_UNSPEC
- the flag is set on attribute passed to nla_parse_nested()
Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
v2: change error messages to mention NLA_F_NESTED explicitly
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | include/net/netlink.h | 11 | ||||
| -rw-r--r-- | lib/nlattr.c | 15 |
2 files changed, 25 insertions, 1 deletions
diff --git a/include/net/netlink.h b/include/net/netlink.h index 679f649748d4..395b4406f4b0 100644 --- a/include/net/netlink.h +++ b/include/net/netlink.h @@ -401,6 +401,8 @@ struct nl_info { * are enforced going forward. * @NL_VALIDATE_STRICT_ATTRS: strict attribute policy parsing (e.g. * U8, U16, U32 must have exact size, etc.) + * @NL_VALIDATE_NESTED: Check that NLA_F_NESTED is set for NLA_NESTED(_ARRAY) + * and unset for other policies. */ enum netlink_validation { NL_VALIDATE_LIBERAL = 0, @@ -408,6 +410,7 @@ enum netlink_validation { NL_VALIDATE_MAXTYPE = BIT(1), NL_VALIDATE_UNSPEC = BIT(2), NL_VALIDATE_STRICT_ATTRS = BIT(3), + NL_VALIDATE_NESTED = BIT(4), }; #define NL_VALIDATE_DEPRECATED_STRICT (NL_VALIDATE_TRAILING |\ @@ -415,7 +418,8 @@ enum netlink_validation { #define NL_VALIDATE_STRICT (NL_VALIDATE_TRAILING |\ NL_VALIDATE_MAXTYPE |\ NL_VALIDATE_UNSPEC |\ - NL_VALIDATE_STRICT_ATTRS) + NL_VALIDATE_STRICT_ATTRS |\ + NL_VALIDATE_NESTED) int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *, struct nlmsghdr *, @@ -1132,6 +1136,11 @@ static inline int nla_parse_nested(struct nlattr *tb[], int maxtype, const struct nla_policy *policy, struct netlink_ext_ack *extack) { + if (!(nla->nla_type & NLA_F_NESTED)) { + NL_SET_ERR_MSG_ATTR(extack, nla, "NLA_F_NESTED is missing"); + return -EINVAL; + } + return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy, NL_VALIDATE_STRICT, extack); } diff --git a/lib/nlattr.c b/lib/nlattr.c index adc919b32bf9..cace9b307781 100644 --- a/lib/nlattr.c +++ b/lib/nlattr.c @@ -184,6 +184,21 @@ static int validate_nla(const struct nlattr *nla, int maxtype, } } + if (validate & NL_VALIDATE_NESTED) { + if ((pt->type == NLA_NESTED || pt->type == NLA_NESTED_ARRAY) && + !(nla->nla_type & NLA_F_NESTED)) { + NL_SET_ERR_MSG_ATTR(extack, nla, + "NLA_F_NESTED is missing"); + return -EINVAL; + } + if (pt->type != NLA_NESTED && pt->type != NLA_NESTED_ARRAY && + pt->type != NLA_UNSPEC && (nla->nla_type & NLA_F_NESTED)) { + NL_SET_ERR_MSG_ATTR(extack, nla, + "NLA_F_NESTED not expected"); + return -EINVAL; + } + } + switch (pt->type) { case NLA_EXACT_LEN: if (attrlen != pt->len) |