summaryrefslogtreecommitdiff
path: root/lib
diff options
context:
space:
mode:
Diffstat (limited to 'lib')
-rw-r--r--lib/nlattr.c248
1 files changed, 200 insertions, 48 deletions
diff --git a/lib/nlattr.c b/lib/nlattr.c
index cace9b307781..bc5b5cf608c4 100644
--- a/lib/nlattr.c
+++ b/lib/nlattr.c
@@ -44,8 +44,22 @@ static const u8 nla_attr_minlen[NLA_TYPE_MAX+1] = {
[NLA_S64] = sizeof(s64),
};
+/*
+ * Nested policies might refer back to the original
+ * policy in some cases, and userspace could try to
+ * abuse that and recurse by nesting in the right
+ * ways. Limit recursion to avoid this problem.
+ */
+#define MAX_POLICY_RECURSION_DEPTH 10
+
+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, unsigned int depth);
+
static int validate_nla_bitfield32(const struct nlattr *nla,
- const u32 *valid_flags_mask)
+ const u32 valid_flags_mask)
{
const struct nla_bitfield32 *bf = nla_data(nla);
@@ -53,11 +67,11 @@ static int validate_nla_bitfield32(const struct nlattr *nla,
return -EINVAL;
/*disallow invalid bit selector */
- if (bf->selector & ~*valid_flags_mask)
+ if (bf->selector & ~valid_flags_mask)
return -EINVAL;
/*disallow invalid bit values */
- if (bf->value & ~*valid_flags_mask)
+ if (bf->value & ~valid_flags_mask)
return -EINVAL;
/*disallow valid bit values that are not selected*/
@@ -70,7 +84,7 @@ 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,
- unsigned int validate)
+ unsigned int validate, unsigned int depth)
{
const struct nlattr *entry;
int rem;
@@ -87,8 +101,9 @@ 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, validate, extack);
+ ret = __nla_validate_parse(nla_data(entry), nla_len(entry),
+ maxtype, policy, validate, extack,
+ NULL, depth + 1);
if (ret < 0)
return ret;
}
@@ -96,17 +111,58 @@ 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)
+void nla_get_range_unsigned(const struct nla_policy *pt,
+ struct netlink_range_validation *range)
{
- bool validate_min, validate_max;
- s64 value;
+ WARN_ON_ONCE(pt->validation_type != NLA_VALIDATE_RANGE_PTR &&
+ (pt->min < 0 || pt->max < 0));
- 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;
+ range->min = 0;
+
+ switch (pt->type) {
+ case NLA_U8:
+ range->max = U8_MAX;
+ break;
+ case NLA_U16:
+ range->max = U16_MAX;
+ break;
+ case NLA_U32:
+ range->max = U32_MAX;
+ break;
+ case NLA_U64:
+ case NLA_MSECS:
+ range->max = U64_MAX;
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ return;
+ }
+
+ 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;
+ default:
+ break;
+ }
+}
+
+static int nla_validate_int_range_unsigned(const struct nla_policy *pt,
+ const struct nlattr *nla,
+ struct netlink_ext_ack *extack)
+{
+ struct netlink_range_validation range;
+ u64 value;
switch (pt->type) {
case NLA_U8:
@@ -118,6 +174,77 @@ static int nla_validate_int_range(const struct nla_policy *pt,
case NLA_U32:
value = nla_get_u32(nla);
break;
+ case NLA_U64:
+ case NLA_MSECS:
+ value = nla_get_u64(nla);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ nla_get_range_unsigned(pt, &range);
+
+ if (value < range.min || value > range.max) {
+ NL_SET_ERR_MSG_ATTR(extack, nla,
+ "integer out of range");
+ return -ERANGE;
+ }
+
+ return 0;
+}
+
+void nla_get_range_signed(const struct nla_policy *pt,
+ struct netlink_range_validation_signed *range)
+{
+ switch (pt->type) {
+ case NLA_S8:
+ range->min = S8_MIN;
+ range->max = S8_MAX;
+ break;
+ case NLA_S16:
+ range->min = S16_MIN;
+ range->max = S16_MAX;
+ break;
+ case NLA_S32:
+ range->min = S32_MIN;
+ range->max = S32_MAX;
+ break;
+ case NLA_S64:
+ range->min = S64_MIN;
+ range->max = S64_MAX;
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ return;
+ }
+
+ 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;
+ default:
+ break;
+ }
+}
+
+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;
+ s64 value;
+
+ switch (pt->type) {
case NLA_S8:
value = nla_get_s8(nla);
break;
@@ -130,22 +257,13 @@ 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)) {
+ nla_get_range_signed(pt, &range);
+
+ if (value < range.min || value > range.max) {
NL_SET_ERR_MSG_ATTR(extack, nla,
"integer out of range");
return -ERANGE;
@@ -154,9 +272,31 @@ 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:
+ case NLA_MSECS:
+ 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)
+ struct netlink_ext_ack *extack, unsigned int depth)
{
u16 strict_start_type = policy[0].strict_start_type;
const struct nla_policy *pt;
@@ -174,7 +314,9 @@ 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_WARN && attrlen != pt->len)) {
+ (pt->type == NLA_EXACT_LEN &&
+ pt->validation_type == NLA_VALIDATE_WARN_TOO_LONG &&
+ 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) {
@@ -200,15 +342,10 @@ static int validate_nla(const struct nlattr *nla, int maxtype,
}
switch (pt->type) {
- case NLA_EXACT_LEN:
- if (attrlen != pt->len)
- goto out_err;
- break;
-
case NLA_REJECT:
- if (extack && pt->validation_data) {
+ if (extack && pt->reject_message) {
NL_SET_BAD_ATTR(extack, nla);
- extack->_msg = pt->validation_data;
+ extack->_msg = pt->reject_message;
return -EINVAL;
}
err = -EINVAL;
@@ -223,7 +360,7 @@ static int validate_nla(const struct nlattr *nla, int maxtype,
if (attrlen != sizeof(struct nla_bitfield32))
goto out_err;
- err = validate_nla_bitfield32(nla, pt->validation_data);
+ err = validate_nla_bitfield32(nla, pt->bitfield32_valid);
if (err)
goto out_err;
break;
@@ -268,10 +405,11 @@ static int validate_nla(const struct nlattr *nla, int maxtype,
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, validate,
- extack);
+ if (pt->nested_policy) {
+ err = __nla_validate_parse(nla_data(nla), nla_len(nla),
+ pt->len, pt->nested_policy,
+ validate, extack, NULL,
+ depth + 1);
if (err < 0) {
/*
* return directly to preserve the inner
@@ -289,12 +427,12 @@ static int validate_nla(const struct nlattr *nla, int maxtype,
break;
if (attrlen < NLA_HDRLEN)
goto out_err;
- if (pt->validation_data) {
+ if (pt->nested_policy) {
int err;
err = nla_validate_array(nla_data(nla), nla_len(nla),
- pt->len, pt->validation_data,
- extack, validate);
+ pt->len, pt->nested_policy,
+ extack, validate, depth);
if (err < 0) {
/*
* return directly to preserve the inner
@@ -317,6 +455,13 @@ static int validate_nla(const struct nlattr *nla, int maxtype,
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;
@@ -332,6 +477,7 @@ 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:
@@ -358,11 +504,17 @@ 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)
+ struct nlattr **tb, unsigned int depth)
{
const struct nlattr *nla;
int rem;
+ if (depth >= MAX_POLICY_RECURSION_DEPTH) {
+ NL_SET_ERR_MSG(extack,
+ "allowed policy recursion depth exceeded");
+ return -EINVAL;
+ }
+
if (tb)
memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1));
@@ -379,7 +531,7 @@ static int __nla_validate_parse(const struct nlattr *head, int len, int maxtype,
}
if (policy) {
int err = validate_nla(nla, maxtype, policy,
- validate, extack);
+ validate, extack, depth);
if (err < 0)
return err;
@@ -421,7 +573,7 @@ int __nla_validate(const struct nlattr *head, int len, int maxtype,
struct netlink_ext_ack *extack)
{
return __nla_validate_parse(head, len, maxtype, policy, validate,
- extack, NULL);
+ extack, NULL, 0);
}
EXPORT_SYMBOL(__nla_validate);
@@ -476,7 +628,7 @@ int __nla_parse(struct nlattr **tb, int maxtype,
struct netlink_ext_ack *extack)
{
return __nla_validate_parse(head, len, maxtype, policy, validate,
- extack, tb);
+ extack, tb, 0);
}
EXPORT_SYMBOL(__nla_parse);
generated by cgit v1.2.3 (git 2.39.0) at 2024-12-13 16:11:26 +0300