From: Michal Kubecek <mkubecek@suse.cz>
To: "David S. Miller" <davem@davemloft.net>
Cc: netdev@vger.kernel.org, Johannes Berg <johannes.berg@intel.com>,
David Ahern <dsahern@gmail.com>,
linux-kernel@vger.kernel.org
Subject: [PATCH net-next 3/3] netlink: add validation of NLA_F_NESTED flag
Date: Thu, 2 May 2019 14:48:00 +0200 (CEST) [thread overview]
Message-ID: <75a0887b3eb70005c272685d8ef9a712f37d7a54.1556798793.git.mkubecek@suse.cz> (raw)
In-Reply-To: <cover.1556798793.git.mkubecek@suse.cz>
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>
---
include/net/netlink.h | 10 +++++++++-
lib/nlattr.c | 15 +++++++++++++++
2 files changed, 24 insertions(+), 1 deletion(-)
diff --git a/include/net/netlink.h b/include/net/netlink.h
index 679f649748d4..55f68e00fb6e 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 +1136,10 @@ 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, "nested attribute expected");
+ 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..92da65cb6637 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,
+ "nested attribute expected");
+ 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,
+ "nested attribute not expected");
+ return -EINVAL;
+ }
+ }
+
switch (pt->type) {
case NLA_EXACT_LEN:
if (attrlen != pt->len)
--
2.21.0
next prev parent reply other threads:[~2019-05-02 12:48 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-02 12:48 [PATCH net-next 0/3] netlink: strict attribute checking follow-up Michal Kubecek
2019-05-02 12:48 ` [PATCH net-next 1/3] genetlink: do not validate dump requests if there is no policy Michal Kubecek
2019-05-02 12:51 ` Johannes Berg
2019-05-02 13:10 ` Michal Kubecek
2019-05-02 13:13 ` Johannes Berg
2019-05-02 13:32 ` Michal Kubecek
2019-05-02 13:36 ` David Ahern
2019-05-02 15:28 ` Johannes Berg
2019-05-02 12:48 ` Michal Kubecek [this message]
2019-05-02 12:54 ` [PATCH net-next 3/3] netlink: add validation of NLA_F_NESTED flag Johannes Berg
2019-05-02 13:14 ` Michal Kubecek
2019-05-02 13:40 ` David Ahern
2019-05-02 15:07 ` Johannes Berg
2019-05-02 12:48 ` [PATCH net-next 2/3] netlink: set bad attribute also on maxtype check Michal Kubecek
2019-05-02 12:52 ` Johannes Berg
2019-05-02 13:37 ` David Ahern
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=75a0887b3eb70005c272685d8ef9a712f37d7a54.1556798793.git.mkubecek@suse.cz \
--to=mkubecek@suse.cz \
--cc=davem@davemloft.net \
--cc=dsahern@gmail.com \
--cc=johannes.berg@intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=netdev@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).