diff options
-rw-r--r-- | include/net/netlink.h | 58 | ||||
-rw-r--r-- | lib/nlattr.c | 60 | ||||
-rw-r--r-- | net/netlink/policy.c | 32 |
3 files changed, 89 insertions, 61 deletions
diff --git a/include/net/netlink.h b/include/net/netlink.h index c0411f14fb53..fdd317f8fde4 100644 --- a/include/net/netlink.h +++ b/include/net/netlink.h @@ -181,8 +181,6 @@ enum { NLA_S64, NLA_BITFIELD32, NLA_REJECT, - NLA_EXACT_LEN, - NLA_MIN_LEN, __NLA_TYPE_MAX, }; @@ -199,11 +197,11 @@ struct netlink_range_validation_signed { enum nla_policy_validation { NLA_VALIDATE_NONE, NLA_VALIDATE_RANGE, + NLA_VALIDATE_RANGE_WARN_TOO_LONG, NLA_VALIDATE_MIN, NLA_VALIDATE_MAX, NLA_VALIDATE_RANGE_PTR, NLA_VALIDATE_FUNCTION, - NLA_VALIDATE_WARN_TOO_LONG, }; /** @@ -222,7 +220,7 @@ enum nla_policy_validation { * NLA_NUL_STRING Maximum length of string (excluding NUL) * NLA_FLAG Unused * NLA_BINARY Maximum length of attribute payload - * NLA_MIN_LEN Minimum length of attribute payload + * (but see also below with the validation type) * NLA_NESTED, * NLA_NESTED_ARRAY Length verification is done by checking len of * nested header (or empty); len field is used if @@ -237,11 +235,6 @@ enum nla_policy_validation { * just like "All other" * NLA_BITFIELD32 Unused * NLA_REJECT Unused - * NLA_EXACT_LEN Attribute should have exactly this length, otherwise - * it is rejected or warned about, the latter happening - * if and only if the `validation_type' is set to - * NLA_VALIDATE_WARN_TOO_LONG. - * NLA_MIN_LEN Minimum length of attribute payload * All other Minimum length of attribute payload * * Meaning of validation union: @@ -296,6 +289,11 @@ enum nla_policy_validation { * pointer to a struct netlink_range_validation_signed * that indicates the min/max values. * Use NLA_POLICY_FULL_RANGE_SIGNED(). + * + * NLA_BINARY If the validation type is like the ones for integers + * above, then the min/max length (not value like for + * integers) of the attribute is enforced. + * * All other Unused - but note that it's a union * * Meaning of `validate' field, use via NLA_POLICY_VALIDATE_FN: @@ -309,7 +307,7 @@ enum nla_policy_validation { * static const struct nla_policy my_policy[ATTR_MAX+1] = { * [ATTR_FOO] = { .type = NLA_U16 }, * [ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ }, - * [ATTR_BAZ] = { .type = NLA_EXACT_LEN, .len = sizeof(struct mystruct) }, + * [ATTR_BAZ] = NLA_POLICY_EXACT_LEN(sizeof(struct mystruct)), * [ATTR_GOO] = NLA_POLICY_BITFIELD32(myvalidflags), * }; */ @@ -335,9 +333,10 @@ struct nla_policy { * nesting validation starts here. * * Additionally, it means that NLA_UNSPEC is actually NLA_REJECT - * for any types >= this, so need to use NLA_MIN_LEN to get the - * previous pure { .len = xyz } behaviour. The advantage of this - * is that types not specified in the policy will be rejected. + * for any types >= this, so need to use NLA_POLICY_MIN_LEN() to + * get the previous pure { .len = xyz } behaviour. The advantage + * of this is that types not specified in the policy will be + * rejected. * * For completely new families it should be set to 1 so that the * validation is enforced for all attributes. For existing ones @@ -349,12 +348,6 @@ struct nla_policy { }; }; -#define NLA_POLICY_EXACT_LEN(_len) { .type = NLA_EXACT_LEN, .len = _len } -#define NLA_POLICY_EXACT_LEN_WARN(_len) \ - { .type = NLA_EXACT_LEN, .len = _len, \ - .validation_type = NLA_VALIDATE_WARN_TOO_LONG, } -#define NLA_POLICY_MIN_LEN(_len) { .type = NLA_MIN_LEN, .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) @@ -370,19 +363,21 @@ struct nla_policy { { .type = NLA_BITFIELD32, .bitfield32_valid = valid } #define __NLA_ENSURE(condition) BUILD_BUG_ON_ZERO(!(condition)) -#define NLA_ENSURE_UINT_TYPE(tp) \ +#define NLA_ENSURE_UINT_OR_BINARY_TYPE(tp) \ (__NLA_ENSURE(tp == NLA_U8 || tp == NLA_U16 || \ tp == NLA_U32 || tp == NLA_U64 || \ - tp == NLA_MSECS) + tp) + tp == NLA_MSECS || \ + tp == NLA_BINARY) + tp) #define NLA_ENSURE_SINT_TYPE(tp) \ (__NLA_ENSURE(tp == NLA_S8 || tp == NLA_S16 || \ tp == NLA_S32 || tp == NLA_S64) + tp) -#define NLA_ENSURE_INT_TYPE(tp) \ +#define NLA_ENSURE_INT_OR_BINARY_TYPE(tp) \ (__NLA_ENSURE(tp == NLA_S8 || tp == NLA_U8 || \ tp == NLA_S16 || tp == NLA_U16 || \ tp == NLA_S32 || tp == NLA_U32 || \ tp == NLA_S64 || tp == NLA_U64 || \ - tp == NLA_MSECS) + tp) + tp == NLA_MSECS || \ + tp == NLA_BINARY) + tp) #define NLA_ENSURE_NO_VALIDATION_PTR(tp) \ (__NLA_ENSURE(tp != NLA_BITFIELD32 && \ tp != NLA_REJECT && \ @@ -390,14 +385,14 @@ struct nla_policy { tp != NLA_NESTED_ARRAY) + tp) #define NLA_POLICY_RANGE(tp, _min, _max) { \ - .type = NLA_ENSURE_INT_TYPE(tp), \ + .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \ .validation_type = NLA_VALIDATE_RANGE, \ .min = _min, \ .max = _max \ } #define NLA_POLICY_FULL_RANGE(tp, _range) { \ - .type = NLA_ENSURE_UINT_TYPE(tp), \ + .type = NLA_ENSURE_UINT_OR_BINARY_TYPE(tp), \ .validation_type = NLA_VALIDATE_RANGE_PTR, \ .range = _range, \ } @@ -409,13 +404,13 @@ struct nla_policy { } #define NLA_POLICY_MIN(tp, _min) { \ - .type = NLA_ENSURE_INT_TYPE(tp), \ + .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \ .validation_type = NLA_VALIDATE_MIN, \ .min = _min, \ } #define NLA_POLICY_MAX(tp, _max) { \ - .type = NLA_ENSURE_INT_TYPE(tp), \ + .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \ .validation_type = NLA_VALIDATE_MAX, \ .max = _max, \ } @@ -427,6 +422,15 @@ struct nla_policy { .len = __VA_ARGS__ + 0, \ } +#define NLA_POLICY_EXACT_LEN(_len) NLA_POLICY_RANGE(NLA_BINARY, _len, _len) +#define NLA_POLICY_EXACT_LEN_WARN(_len) { \ + .type = NLA_BINARY, \ + .validation_type = NLA_VALIDATE_RANGE_WARN_TOO_LONG, \ + .min = _len, \ + .max = _len \ +} +#define NLA_POLICY_MIN_LEN(_len) NLA_POLICY_MIN(NLA_BINARY, _len) + /** * struct nl_info - netlink source information * @nlh: Netlink message header of original request diff --git a/lib/nlattr.c b/lib/nlattr.c index bc5b5cf608c4..665bdaff02c8 100644 --- a/lib/nlattr.c +++ b/lib/nlattr.c @@ -124,6 +124,7 @@ void nla_get_range_unsigned(const struct nla_policy *pt, range->max = U8_MAX; break; case NLA_U16: + case NLA_BINARY: range->max = U16_MAX; break; case NLA_U32: @@ -140,6 +141,7 @@ void nla_get_range_unsigned(const struct nla_policy *pt, switch (pt->validation_type) { case NLA_VALIDATE_RANGE: + case NLA_VALIDATE_RANGE_WARN_TOO_LONG: range->min = pt->min; range->max = pt->max; break; @@ -157,9 +159,10 @@ void nla_get_range_unsigned(const struct nla_policy *pt, } } -static int nla_validate_int_range_unsigned(const struct nla_policy *pt, - const struct nlattr *nla, - struct netlink_ext_ack *extack) +static int nla_validate_range_unsigned(const struct nla_policy *pt, + const struct nlattr *nla, + struct netlink_ext_ack *extack, + unsigned int validate) { struct netlink_range_validation range; u64 value; @@ -178,15 +181,39 @@ static int nla_validate_int_range_unsigned(const struct nla_policy *pt, case NLA_MSECS: value = nla_get_u64(nla); break; + case NLA_BINARY: + value = nla_len(nla); + break; default: return -EINVAL; } nla_get_range_unsigned(pt, &range); + if (pt->validation_type == NLA_VALIDATE_RANGE_WARN_TOO_LONG && + pt->type == NLA_BINARY && value > range.max) { + pr_warn_ratelimited("netlink: '%s': attribute type %d has an invalid length.\n", + current->comm, pt->type); + if (validate & NL_VALIDATE_STRICT_ATTRS) { + NL_SET_ERR_MSG_ATTR(extack, nla, + "invalid attribute length"); + return -EINVAL; + } + + /* this assumes min <= max (don't validate against min) */ + return 0; + } + if (value < range.min || value > range.max) { - NL_SET_ERR_MSG_ATTR(extack, nla, - "integer out of range"); + bool binary = pt->type == NLA_BINARY; + + if (binary) + NL_SET_ERR_MSG_ATTR(extack, nla, + "binary attribute size out of range"); + else + NL_SET_ERR_MSG_ATTR(extack, nla, + "integer out of range"); + return -ERANGE; } @@ -274,7 +301,8 @@ static int nla_validate_int_range_signed(const struct nla_policy *pt, static int nla_validate_int_range(const struct nla_policy *pt, const struct nlattr *nla, - struct netlink_ext_ack *extack) + struct netlink_ext_ack *extack, + unsigned int validate) { switch (pt->type) { case NLA_U8: @@ -282,7 +310,8 @@ static int nla_validate_int_range(const struct nla_policy *pt, case NLA_U32: case NLA_U64: case NLA_MSECS: - return nla_validate_int_range_unsigned(pt, nla, extack); + case NLA_BINARY: + return nla_validate_range_unsigned(pt, nla, extack, validate); case NLA_S8: case NLA_S16: case NLA_S32: @@ -313,10 +342,7 @@ 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]) || - (pt->type == NLA_EXACT_LEN && - pt->validation_type == NLA_VALIDATE_WARN_TOO_LONG && - attrlen != pt->len)) { + if (nla_attr_len[pt->type] && attrlen != nla_attr_len[pt->type]) { pr_warn_ratelimited("netlink: '%s': attribute type %d has an invalid length.\n", current->comm, type); if (validate & NL_VALIDATE_STRICT_ATTRS) { @@ -449,19 +475,10 @@ static int validate_nla(const struct nlattr *nla, int maxtype, "Unsupported attribute"); return -EINVAL; } - /* fall through */ - case NLA_MIN_LEN: if (attrlen < pt->len) goto out_err; break; - case NLA_EXACT_LEN: - if (pt->validation_type != NLA_VALIDATE_WARN_TOO_LONG) { - if (attrlen != pt->len) - goto out_err; - break; - } - /* fall through */ default: if (pt->len) minlen = pt->len; @@ -479,9 +496,10 @@ static int validate_nla(const struct nlattr *nla, int maxtype, break; case NLA_VALIDATE_RANGE_PTR: case NLA_VALIDATE_RANGE: + case NLA_VALIDATE_RANGE_WARN_TOO_LONG: case NLA_VALIDATE_MIN: case NLA_VALIDATE_MAX: - err = nla_validate_int_range(pt, nla, extack); + err = nla_validate_int_range(pt, nla, extack, validate); if (err) return err; break; diff --git a/net/netlink/policy.c b/net/netlink/policy.c index f6491853c797..46c11c9c212a 100644 --- a/net/netlink/policy.c +++ b/net/netlink/policy.c @@ -251,12 +251,6 @@ send_attribute: pt->bitfield32_valid)) goto nla_put_failure; break; - case NLA_EXACT_LEN: - type = NL_ATTR_TYPE_BINARY; - if (nla_put_u32(skb, NL_POLICY_TYPE_ATTR_MIN_LENGTH, pt->len) || - nla_put_u32(skb, NL_POLICY_TYPE_ATTR_MAX_LENGTH, pt->len)) - goto nla_put_failure; - break; case NLA_STRING: case NLA_NUL_STRING: case NLA_BINARY: @@ -266,14 +260,26 @@ send_attribute: type = NL_ATTR_TYPE_NUL_STRING; else type = NL_ATTR_TYPE_BINARY; - if (pt->len && nla_put_u32(skb, NL_POLICY_TYPE_ATTR_MAX_LENGTH, - pt->len)) - goto nla_put_failure; - break; - case NLA_MIN_LEN: - type = NL_ATTR_TYPE_BINARY; - if (nla_put_u32(skb, NL_POLICY_TYPE_ATTR_MIN_LENGTH, pt->len)) + + if (pt->validation_type != NLA_VALIDATE_NONE) { + struct netlink_range_validation range; + + nla_get_range_unsigned(pt, &range); + + if (range.min && + nla_put_u32(skb, NL_POLICY_TYPE_ATTR_MIN_LENGTH, + range.min)) + goto nla_put_failure; + + if (range.max < U16_MAX && + nla_put_u32(skb, NL_POLICY_TYPE_ATTR_MAX_LENGTH, + range.max)) + goto nla_put_failure; + } else if (pt->len && + nla_put_u32(skb, NL_POLICY_TYPE_ATTR_MAX_LENGTH, + pt->len)) { goto nla_put_failure; + } break; case NLA_FLAG: type = NL_ATTR_TYPE_FLAG; |