netlink: move extack setting into validate_nla()
This unifies the code between nla_parse() which sets the bad attribute pointer and an error message, and nla_validate() which only sets the bad attribute pointer. It also cleans up the code for NLA_REJECT and paves the way for nested policy validation, as it will allow us to easily skip setting the "generic" message without any extra args like the **error_msg now, just passing the extack through is now enough. While at it, remove the unnecessary label in nla_parse(). Suggested-by: David Ahern <dsahern@gmail.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
parent
48fde90a78
commit
c29f1845b2
66
lib/nlattr.c
66
lib/nlattr.c
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@ -69,10 +69,11 @@ static int validate_nla_bitfield32(const struct nlattr *nla,
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static int validate_nla(const struct nlattr *nla, int maxtype,
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const struct nla_policy *policy,
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const char **error_msg)
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struct netlink_ext_ack *extack)
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{
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const struct nla_policy *pt;
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int minlen = 0, attrlen = nla_len(nla), type = nla_type(nla);
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int err = -ERANGE;
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if (type <= 0 || type > maxtype)
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return 0;
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@ -90,24 +91,31 @@ static int validate_nla(const struct nlattr *nla, int maxtype,
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switch (pt->type) {
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case NLA_EXACT_LEN:
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if (attrlen != pt->len)
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return -ERANGE;
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goto out_err;
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break;
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case NLA_REJECT:
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if (pt->validation_data && error_msg)
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*error_msg = pt->validation_data;
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if (extack && pt->validation_data) {
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NL_SET_BAD_ATTR(extack, nla);
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extack->_msg = pt->validation_data;
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return -EINVAL;
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}
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err = -EINVAL;
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goto out_err;
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case NLA_FLAG:
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if (attrlen > 0)
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return -ERANGE;
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goto out_err;
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break;
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case NLA_BITFIELD32:
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if (attrlen != sizeof(struct nla_bitfield32))
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return -ERANGE;
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goto out_err;
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return validate_nla_bitfield32(nla, pt->validation_data);
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err = validate_nla_bitfield32(nla, pt->validation_data);
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if (err)
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goto out_err;
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break;
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case NLA_NUL_STRING:
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if (pt->len)
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@ -115,13 +123,15 @@ static int validate_nla(const struct nlattr *nla, int maxtype,
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else
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minlen = attrlen;
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if (!minlen || memchr(nla_data(nla), '\0', minlen) == NULL)
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return -EINVAL;
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if (!minlen || memchr(nla_data(nla), '\0', minlen) == NULL) {
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err = -EINVAL;
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goto out_err;
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}
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/* fall through */
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case NLA_STRING:
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if (attrlen < 1)
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return -ERANGE;
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goto out_err;
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if (pt->len) {
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char *buf = nla_data(nla);
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@ -130,13 +140,13 @@ static int validate_nla(const struct nlattr *nla, int maxtype,
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attrlen--;
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if (attrlen > pt->len)
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return -ERANGE;
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goto out_err;
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}
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break;
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case NLA_BINARY:
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if (pt->len && attrlen > pt->len)
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return -ERANGE;
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goto out_err;
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break;
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case NLA_NESTED:
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@ -152,10 +162,13 @@ static int validate_nla(const struct nlattr *nla, int maxtype,
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minlen = nla_attr_minlen[pt->type];
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if (attrlen < minlen)
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return -ERANGE;
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goto out_err;
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}
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return 0;
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out_err:
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NL_SET_ERR_MSG_ATTR(extack, nla, "Attribute failed policy validation");
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return err;
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}
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/**
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@ -180,13 +193,11 @@ int nla_validate(const struct nlattr *head, int len, int maxtype,
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int rem;
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nla_for_each_attr(nla, head, len, rem) {
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int err = validate_nla(nla, maxtype, policy, NULL);
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int err = validate_nla(nla, maxtype, policy, extack);
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if (err < 0) {
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NL_SET_BAD_ATTR(extack, nla);
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if (err < 0)
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return err;
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}
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}
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return 0;
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}
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@ -241,7 +252,7 @@ int nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head,
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struct netlink_ext_ack *extack)
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{
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const struct nlattr *nla;
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int rem, err;
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int rem;
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memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1));
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@ -249,17 +260,12 @@ int nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head,
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u16 type = nla_type(nla);
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if (type > 0 && type <= maxtype) {
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static const char _msg[] = "Attribute failed policy validation";
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const char *msg = _msg;
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if (policy) {
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err = validate_nla(nla, maxtype, policy, &msg);
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if (err < 0) {
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NL_SET_BAD_ATTR(extack, nla);
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if (extack)
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extack->_msg = msg;
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goto errout;
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}
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int err = validate_nla(nla, maxtype, policy,
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extack);
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if (err < 0)
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return err;
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}
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tb[type] = (struct nlattr *)nla;
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@ -270,9 +276,7 @@ int nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head,
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pr_warn_ratelimited("netlink: %d bytes leftover after parsing attributes in process `%s'.\n",
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rem, current->comm);
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err = 0;
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errout:
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return err;
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return 0;
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}
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EXPORT_SYMBOL(nla_parse);
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