diff options
| -rw-r--r-- | include/net/netlink.h | 13 | ||||
| -rw-r--r-- | lib/nlattr.c | 8 |
2 files changed, 20 insertions, 1 deletions
diff --git a/include/net/netlink.h b/include/net/netlink.h index b318b0a9f6c3..318b1ded3833 100644 --- a/include/net/netlink.h +++ b/include/net/netlink.h @@ -181,6 +181,8 @@ enum { NLA_S64, NLA_BITFIELD32, NLA_REJECT, + NLA_EXACT_LEN, + NLA_EXACT_LEN_WARN, __NLA_TYPE_MAX, }; @@ -211,6 +213,10 @@ enum { * just like "All other" * NLA_BITFIELD32 Unused * NLA_REJECT Unused + * NLA_EXACT_LEN Attribute must have exactly this length, otherwise + * it is rejected. + * NLA_EXACT_LEN_WARN Attribute should have exactly this length, a warning + * is logged if it is longer, shorter is rejected. * All other Minimum length of attribute payload * * Meaning of `validation_data' field: @@ -236,6 +242,13 @@ struct nla_policy { void *validation_data; }; +#define NLA_POLICY_EXACT_LEN(_len) { .type = NLA_EXACT_LEN, .len = _len } +#define NLA_POLICY_EXACT_LEN_WARN(_len) { .type = NLA_EXACT_LEN_WARN, \ + .len = _len } + +#define NLA_POLICY_ETH_ADDR NLA_POLICY_EXACT_LEN(ETH_ALEN) +#define NLA_POLICY_ETH_ADDR_COMPAT NLA_POLICY_EXACT_LEN_WARN(ETH_ALEN) + /** * struct nl_info - netlink source information * @nlh: Netlink message header of original request diff --git a/lib/nlattr.c b/lib/nlattr.c index 36d74b079151..bb6fe5ed4ecf 100644 --- a/lib/nlattr.c +++ b/lib/nlattr.c @@ -82,12 +82,18 @@ static int validate_nla(const struct nlattr *nla, int maxtype, BUG_ON(pt->type > NLA_TYPE_MAX); - if (nla_attr_len[pt->type] && attrlen != nla_attr_len[pt->type]) { + if ((nla_attr_len[pt->type] && attrlen != nla_attr_len[pt->type]) || + (pt->type == NLA_EXACT_LEN_WARN && attrlen != pt->len)) { pr_warn_ratelimited("netlink: '%s': attribute type %d has an invalid length.\n", current->comm, type); } switch (pt->type) { + case NLA_EXACT_LEN: + if (attrlen != pt->len) + return -ERANGE; + break; + case NLA_REJECT: if (pt->validation_data && error_msg) *error_msg = pt->validation_data; |