diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/nlattr.c | 171 |
1 files changed, 88 insertions, 83 deletions
diff --git a/lib/nlattr.c b/lib/nlattr.c index 465c9e8ef8a5..af0f8b0309c6 100644 --- a/lib/nlattr.c +++ b/lib/nlattr.c @@ -69,7 +69,8 @@ static int validate_nla_bitfield32(const struct nlattr *nla, static int nla_validate_array(const struct nlattr *head, int len, int maxtype, const struct nla_policy *policy, - struct netlink_ext_ack *extack) + struct netlink_ext_ack *extack, + unsigned int validate) { const struct nlattr *entry; int rem; @@ -86,8 +87,8 @@ static int nla_validate_array(const struct nlattr *head, int len, int maxtype, return -ERANGE; } - ret = nla_validate(nla_data(entry), nla_len(entry), - maxtype, policy, extack); + ret = __nla_validate(nla_data(entry), nla_len(entry), + maxtype, policy, validate, extack); if (ret < 0) return ret; } @@ -154,7 +155,7 @@ static int nla_validate_int_range(const struct nla_policy *pt, } static int validate_nla(const struct nlattr *nla, int maxtype, - const struct nla_policy *policy, + const struct nla_policy *policy, unsigned int validate, struct netlink_ext_ack *extack) { const struct nla_policy *pt; @@ -172,6 +173,11 @@ static int validate_nla(const struct nlattr *nla, int maxtype, (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); + if (validate & NL_VALIDATE_STRICT_ATTRS) { + NL_SET_ERR_MSG_ATTR(extack, nla, + "invalid attribute length"); + return -EINVAL; + } } switch (pt->type) { @@ -244,8 +250,9 @@ static int validate_nla(const struct nlattr *nla, int maxtype, if (attrlen < NLA_HDRLEN) goto out_err; if (pt->validation_data) { - err = nla_validate(nla_data(nla), nla_len(nla), pt->len, - pt->validation_data, extack); + err = __nla_validate(nla_data(nla), nla_len(nla), pt->len, + pt->validation_data, validate, + extack); if (err < 0) { /* * return directly to preserve the inner @@ -268,7 +275,7 @@ static int validate_nla(const struct nlattr *nla, int maxtype, err = nla_validate_array(nla_data(nla), nla_len(nla), pt->len, pt->validation_data, - extack); + extack, validate); if (err < 0) { /* * return directly to preserve the inner @@ -280,6 +287,12 @@ static int validate_nla(const struct nlattr *nla, int maxtype, break; case NLA_UNSPEC: + if (validate & NL_VALIDATE_UNSPEC) { + NL_SET_ERR_MSG_ATTR(extack, nla, + "Unsupported attribute"); + return -EINVAL; + } + /* fall through */ case NLA_MIN_LEN: if (attrlen < pt->len) goto out_err; @@ -322,37 +335,75 @@ out_err: return err; } +static int __nla_validate_parse(const struct nlattr *head, int len, int maxtype, + const struct nla_policy *policy, + unsigned int validate, + struct netlink_ext_ack *extack, + struct nlattr **tb) +{ + const struct nlattr *nla; + int rem; + + if (tb) + memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1)); + + nla_for_each_attr(nla, head, len, rem) { + u16 type = nla_type(nla); + + if (type == 0 || type > maxtype) { + if (validate & NL_VALIDATE_MAXTYPE) { + NL_SET_ERR_MSG(extack, "Unknown attribute type"); + return -EINVAL; + } + continue; + } + if (policy) { + int err = validate_nla(nla, maxtype, policy, + validate, extack); + + if (err < 0) + return err; + } + + if (tb) + tb[type] = (struct nlattr *)nla; + } + + if (unlikely(rem > 0)) { + pr_warn_ratelimited("netlink: %d bytes leftover after parsing attributes in process `%s'.\n", + rem, current->comm); + NL_SET_ERR_MSG(extack, "bytes leftover after parsing attributes"); + if (validate & NL_VALIDATE_TRAILING) + return -EINVAL; + } + + return 0; +} + /** - * nla_validate - Validate a stream of attributes + * __nla_validate - Validate a stream of attributes * @head: head of attribute stream * @len: length of attribute stream * @maxtype: maximum attribute type to be expected * @policy: validation policy + * @validate: validation strictness * @extack: extended ACK report struct * * Validates all attributes in the specified attribute stream against the - * specified policy. Attributes with a type exceeding maxtype will be - * ignored. See documenation of struct nla_policy for more details. + * specified policy. Validation depends on the validate flags passed, see + * &enum netlink_validation for more details on that. + * See documenation of struct nla_policy for more details. * * Returns 0 on success or a negative error code. */ -int nla_validate(const struct nlattr *head, int len, int maxtype, - const struct nla_policy *policy, - struct netlink_ext_ack *extack) +int __nla_validate(const struct nlattr *head, int len, int maxtype, + const struct nla_policy *policy, unsigned int validate, + struct netlink_ext_ack *extack) { - const struct nlattr *nla; - int rem; - - nla_for_each_attr(nla, head, len, rem) { - int err = validate_nla(nla, maxtype, policy, extack); - - if (err < 0) - return err; - } - - return 0; + return __nla_validate_parse(head, len, maxtype, policy, validate, + extack, NULL); } -EXPORT_SYMBOL(nla_validate); +EXPORT_SYMBOL(__nla_validate); /** * nla_policy_len - Determin the max. length of a policy @@ -384,76 +435,30 @@ nla_policy_len(const struct nla_policy *p, int n) EXPORT_SYMBOL(nla_policy_len); /** - * nla_parse - Parse a stream of attributes into a tb buffer + * __nla_parse - Parse a stream of attributes into a tb buffer * @tb: destination array with maxtype+1 elements * @maxtype: maximum attribute type to be expected * @head: head of attribute stream * @len: length of attribute stream * @policy: validation policy + * @validate: validation strictness + * @extack: extended ACK pointer * * Parses a stream of attributes and stores a pointer to each attribute in - * the tb array accessible via the attribute type. Attributes with a type - * exceeding maxtype will be silently ignored for backwards compatibility - * reasons. policy may be set to NULL if no validation is required. + * the tb array accessible via the attribute type. + * Validation is controlled by the @validate parameter. * * Returns 0 on success or a negative error code. */ -static int __nla_parse(struct nlattr **tb, int maxtype, - const struct nlattr *head, int len, - bool strict, const struct nla_policy *policy, - struct netlink_ext_ack *extack) -{ - const struct nlattr *nla; - int rem; - - memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1)); - - nla_for_each_attr(nla, head, len, rem) { - u16 type = nla_type(nla); - - if (type == 0 || type > maxtype) { - if (strict) { - NL_SET_ERR_MSG(extack, "Unknown attribute type"); - return -EINVAL; - } - continue; - } - if (policy) { - int err = validate_nla(nla, maxtype, policy, extack); - - if (err < 0) - return err; - } - - tb[type] = (struct nlattr *)nla; - } - - if (unlikely(rem > 0)) { - pr_warn_ratelimited("netlink: %d bytes leftover after parsing attributes in process `%s'.\n", - rem, current->comm); - NL_SET_ERR_MSG(extack, "bytes leftover after parsing attributes"); - if (strict) - return -EINVAL; - } - - return 0; -} - -int nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head, - int len, const struct nla_policy *policy, - struct netlink_ext_ack *extack) -{ - return __nla_parse(tb, maxtype, head, len, false, policy, extack); -} -EXPORT_SYMBOL(nla_parse); - -int nla_parse_strict(struct nlattr **tb, int maxtype, const struct nlattr *head, - int len, const struct nla_policy *policy, - struct netlink_ext_ack *extack) +int __nla_parse(struct nlattr **tb, int maxtype, + const struct nlattr *head, int len, + const struct nla_policy *policy, unsigned int validate, + struct netlink_ext_ack *extack) { - return __nla_parse(tb, maxtype, head, len, true, policy, extack); + return __nla_validate_parse(head, len, maxtype, policy, validate, + extack, tb); } -EXPORT_SYMBOL(nla_parse_strict); +EXPORT_SYMBOL(__nla_parse); /** * nla_find - Find a specific attribute in a stream of attributes |