From d06a09b94c618c96ced584dd4611a888c8856b8d Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Thu, 30 Apr 2020 22:13:08 +0200 Subject: netlink: extend policy range validation Using a pointer to a struct indicating the min/max values, extend the ability to do range validation for arbitrary values. Small values in the s16 range can be kept in the policy directly. Signed-off-by: Johannes Berg Signed-off-by: David S. Miller --- lib/nlattr.c | 113 ++++++++++++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 92 insertions(+), 21 deletions(-) (limited to 'lib/nlattr.c') diff --git a/lib/nlattr.c b/lib/nlattr.c index 7f7ebd89caa4..a8beb173f558 100644 --- a/lib/nlattr.c +++ b/lib/nlattr.c @@ -111,17 +111,34 @@ static int nla_validate_array(const struct nlattr *head, int len, int maxtype, return 0; } -static int nla_validate_int_range(const struct nla_policy *pt, - const struct nlattr *nla, - struct netlink_ext_ack *extack) +static int nla_validate_int_range_unsigned(const struct nla_policy *pt, + const struct nlattr *nla, + struct netlink_ext_ack *extack) { - bool validate_min, validate_max; - s64 value; + struct netlink_range_validation _range = { + .min = 0, + .max = U64_MAX, + }, *range = &_range; + u64 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; + WARN_ON_ONCE(pt->validation_type != NLA_VALIDATE_RANGE_PTR && + (pt->min < 0 || pt->max < 0)); + + switch (pt->validation_type) { + case NLA_VALIDATE_RANGE: + range->min = pt->min; + range->max = pt->max; + break; + case NLA_VALIDATE_RANGE_PTR: + range = pt->range; + break; + case NLA_VALIDATE_MIN: + range->min = pt->min; + break; + case NLA_VALIDATE_MAX: + range->max = pt->max; + break; + } switch (pt->type) { case NLA_U8: @@ -133,6 +150,49 @@ static int nla_validate_int_range(const struct nla_policy *pt, case NLA_U32: value = nla_get_u32(nla); break; + case NLA_U64: + value = nla_get_u64(nla); + break; + default: + return -EINVAL; + } + + if (value < range->min || value > range->max) { + NL_SET_ERR_MSG_ATTR(extack, nla, + "integer out of range"); + return -ERANGE; + } + + return 0; +} + +static int nla_validate_int_range_signed(const struct nla_policy *pt, + const struct nlattr *nla, + struct netlink_ext_ack *extack) +{ + struct netlink_range_validation_signed _range = { + .min = S64_MIN, + .max = S64_MAX, + }, *range = &_range; + s64 value; + + switch (pt->validation_type) { + case NLA_VALIDATE_RANGE: + range->min = pt->min; + range->max = pt->max; + break; + case NLA_VALIDATE_RANGE_PTR: + range = pt->range_signed; + break; + case NLA_VALIDATE_MIN: + range->min = pt->min; + break; + case NLA_VALIDATE_MAX: + range->max = pt->max; + break; + } + + switch (pt->type) { case NLA_S8: value = nla_get_s8(nla); break; @@ -145,22 +205,11 @@ static int nla_validate_int_range(const struct nla_policy *pt, 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)) { + if (value < range->min || value > range->max) { NL_SET_ERR_MSG_ATTR(extack, nla, "integer out of range"); return -ERANGE; @@ -169,6 +218,27 @@ static int nla_validate_int_range(const struct nla_policy *pt, return 0; } +static int nla_validate_int_range(const struct nla_policy *pt, + const struct nlattr *nla, + struct netlink_ext_ack *extack) +{ + switch (pt->type) { + case NLA_U8: + case NLA_U16: + case NLA_U32: + case NLA_U64: + return nla_validate_int_range_unsigned(pt, nla, extack); + case NLA_S8: + case NLA_S16: + case NLA_S32: + case NLA_S64: + return nla_validate_int_range_signed(pt, nla, extack); + default: + WARN_ON(1); + return -EINVAL; + } +} + static int validate_nla(const struct nlattr *nla, int maxtype, const struct nla_policy *policy, unsigned int validate, struct netlink_ext_ack *extack, unsigned int depth) @@ -348,6 +418,7 @@ static int validate_nla(const struct nlattr *nla, int maxtype, case NLA_VALIDATE_NONE: /* nothing to do */ break; + case NLA_VALIDATE_RANGE_PTR: case NLA_VALIDATE_RANGE: case NLA_VALIDATE_MIN: case NLA_VALIDATE_MAX: -- cgit v1.2.3