diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/nlattr.c | 266 |
1 files changed, 213 insertions, 53 deletions
diff --git a/lib/nlattr.c b/lib/nlattr.c index bb6fe5ed4ecf..d26de6156b97 100644 --- a/lib/nlattr.c +++ b/lib/nlattr.c @@ -45,12 +45,11 @@ static const u8 nla_attr_minlen[NLA_TYPE_MAX+1] = { }; static int validate_nla_bitfield32(const struct nlattr *nla, - u32 *valid_flags_allowed) + const u32 *valid_flags_mask) { const struct nla_bitfield32 *bf = nla_data(nla); - u32 *valid_flags_mask = valid_flags_allowed; - if (!valid_flags_allowed) + if (!valid_flags_mask) return -EINVAL; /*disallow invalid bit selector */ @@ -68,12 +67,99 @@ static int validate_nla_bitfield32(const struct nlattr *nla, return 0; } +static int nla_validate_array(const struct nlattr *head, int len, int maxtype, + const struct nla_policy *policy, + struct netlink_ext_ack *extack) +{ + const struct nlattr *entry; + int rem; + + nla_for_each_attr(entry, head, len, rem) { + int ret; + + if (nla_len(entry) == 0) + continue; + + if (nla_len(entry) < NLA_HDRLEN) { + NL_SET_ERR_MSG_ATTR(extack, entry, + "Array element too short"); + return -ERANGE; + } + + ret = nla_validate(nla_data(entry), nla_len(entry), + maxtype, policy, extack); + if (ret < 0) + return ret; + } + + return 0; +} + +static int nla_validate_int_range(const struct nla_policy *pt, + const struct nlattr *nla, + struct netlink_ext_ack *extack) +{ + bool validate_min, validate_max; + s64 value; + + validate_min = pt->validation_type == NLA_VALIDATE_RANGE || + pt->validation_type == NLA_VALIDATE_MIN; + validate_max = pt->validation_type == NLA_VALIDATE_RANGE || + pt->validation_type == NLA_VALIDATE_MAX; + + switch (pt->type) { + case NLA_U8: + value = nla_get_u8(nla); + break; + case NLA_U16: + value = nla_get_u16(nla); + break; + case NLA_U32: + value = nla_get_u32(nla); + break; + case NLA_S8: + value = nla_get_s8(nla); + break; + case NLA_S16: + value = nla_get_s16(nla); + break; + case NLA_S32: + value = nla_get_s32(nla); + break; + case NLA_S64: + value = nla_get_s64(nla); + break; + case NLA_U64: + /* treat this one specially, since it may not fit into s64 */ + if ((validate_min && nla_get_u64(nla) < pt->min) || + (validate_max && nla_get_u64(nla) > pt->max)) { + NL_SET_ERR_MSG_ATTR(extack, nla, + "integer out of range"); + return -ERANGE; + } + return 0; + default: + WARN_ON(1); + return -EINVAL; + } + + if ((validate_min && value < pt->min) || + (validate_max && value > pt->max)) { + NL_SET_ERR_MSG_ATTR(extack, nla, + "integer out of range"); + return -ERANGE; + } + + return 0; +} + static int validate_nla(const struct nlattr *nla, int maxtype, const struct nla_policy *policy, - const char **error_msg) + struct netlink_ext_ack *extack) { const struct nla_policy *pt; int minlen = 0, attrlen = nla_len(nla), type = nla_type(nla); + int err = -ERANGE; if (type <= 0 || type > maxtype) return 0; @@ -91,24 +177,31 @@ static int validate_nla(const struct nlattr *nla, int maxtype, switch (pt->type) { case NLA_EXACT_LEN: if (attrlen != pt->len) - return -ERANGE; + goto out_err; break; case NLA_REJECT: - if (pt->validation_data && error_msg) - *error_msg = pt->validation_data; - return -EINVAL; + if (extack && pt->validation_data) { + NL_SET_BAD_ATTR(extack, nla); + extack->_msg = pt->validation_data; + return -EINVAL; + } + err = -EINVAL; + goto out_err; case NLA_FLAG: if (attrlen > 0) - return -ERANGE; + goto out_err; break; case NLA_BITFIELD32: if (attrlen != sizeof(struct nla_bitfield32)) - return -ERANGE; + goto out_err; - return validate_nla_bitfield32(nla, pt->validation_data); + err = validate_nla_bitfield32(nla, pt->validation_data); + if (err) + goto out_err; + break; case NLA_NUL_STRING: if (pt->len) @@ -116,13 +209,15 @@ static int validate_nla(const struct nlattr *nla, int maxtype, else minlen = attrlen; - if (!minlen || memchr(nla_data(nla), '\0', minlen) == NULL) - return -EINVAL; + if (!minlen || memchr(nla_data(nla), '\0', minlen) == NULL) { + err = -EINVAL; + goto out_err; + } /* fall through */ case NLA_STRING: if (attrlen < 1) - return -ERANGE; + goto out_err; if (pt->len) { char *buf = nla_data(nla); @@ -131,32 +226,58 @@ static int validate_nla(const struct nlattr *nla, int maxtype, attrlen--; if (attrlen > pt->len) - return -ERANGE; + goto out_err; } break; case NLA_BINARY: if (pt->len && attrlen > pt->len) - return -ERANGE; + goto out_err; break; - case NLA_NESTED_COMPAT: - if (attrlen < pt->len) - return -ERANGE; - if (attrlen < NLA_ALIGN(pt->len)) - break; - if (attrlen < NLA_ALIGN(pt->len) + NLA_HDRLEN) - return -ERANGE; - nla = nla_data(nla) + NLA_ALIGN(pt->len); - if (attrlen < NLA_ALIGN(pt->len) + NLA_HDRLEN + nla_len(nla)) - return -ERANGE; - break; case NLA_NESTED: /* a nested attributes is allowed to be empty; if its not, * it must have a size of at least NLA_HDRLEN. */ if (attrlen == 0) break; + 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); + if (err < 0) { + /* + * return directly to preserve the inner + * error message/attribute pointer + */ + return err; + } + } + break; + case NLA_NESTED_ARRAY: + /* a nested array attribute is allowed to be empty; if its not, + * it must have a size of at least NLA_HDRLEN. + */ + if (attrlen == 0) + break; + if (attrlen < NLA_HDRLEN) + goto out_err; + if (pt->validation_data) { + int err; + + err = nla_validate_array(nla_data(nla), nla_len(nla), + pt->len, pt->validation_data, + extack); + if (err < 0) { + /* + * return directly to preserve the inner + * error message/attribute pointer + */ + return err; + } + } + break; default: if (pt->len) minlen = pt->len; @@ -164,10 +285,34 @@ static int validate_nla(const struct nlattr *nla, int maxtype, minlen = nla_attr_minlen[pt->type]; if (attrlen < minlen) - return -ERANGE; + goto out_err; + } + + /* further validation */ + switch (pt->validation_type) { + case NLA_VALIDATE_NONE: + /* nothing to do */ + break; + case NLA_VALIDATE_RANGE: + case NLA_VALIDATE_MIN: + case NLA_VALIDATE_MAX: + err = nla_validate_int_range(pt, nla, extack); + if (err) + return err; + break; + case NLA_VALIDATE_FUNCTION: + if (pt->validate) { + err = pt->validate(nla, extack); + if (err) + return err; + } + break; } return 0; +out_err: + NL_SET_ERR_MSG_ATTR(extack, nla, "Attribute failed policy validation"); + return err; } /** @@ -192,12 +337,10 @@ int nla_validate(const struct nlattr *head, int len, int maxtype, int rem; nla_for_each_attr(nla, head, len, rem) { - int err = validate_nla(nla, maxtype, policy, NULL); + int err = validate_nla(nla, maxtype, policy, extack); - if (err < 0) { - NL_SET_BAD_ATTR(extack, nla); + if (err < 0) return err; - } } return 0; @@ -248,46 +391,63 @@ EXPORT_SYMBOL(nla_policy_len); * * Returns 0 on success or a negative error code. */ -int nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head, - int len, const struct nla_policy *policy, - struct netlink_ext_ack *extack) +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, err; + 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) { - static const char _msg[] = "Attribute failed policy validation"; - const char *msg = _msg; - - if (policy) { - err = validate_nla(nla, maxtype, policy, &msg); - if (err < 0) { - NL_SET_BAD_ATTR(extack, nla); - if (extack) - extack->_msg = msg; - goto errout; - } + 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); - tb[type] = (struct nlattr *)nla; + if (err < 0) + return err; } + + tb[type] = (struct nlattr *)nla; } - if (unlikely(rem > 0)) + 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; + } - err = 0; -errout: - return err; + 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) +{ + return __nla_parse(tb, maxtype, head, len, true, policy, extack); +} +EXPORT_SYMBOL(nla_parse_strict); + /** * nla_find - Find a specific attribute in a stream of attributes * @head: head of attribute stream |