diff mbox series

[47/74] backport: implement NLA_POLICY_RANGE for NLA_BINARY

Message ID 20240524190907.84d051bc3c68.Ife595e2dc94955bda3d7d3089ec6a219fde272c1@changeid (mailing list archive)
State New
Headers show
Series backport updates from Intel | expand

Commit Message

Johannes Berg May 24, 2024, 5:07 p.m. UTC 
From: Luca Coelho <luciano.coelho@intel.com>

The range checks for NLA_BINARY are supported since v5.10.  Unwrap the
macros and introduce a new function to test type.

Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 backport/backport-include/net/netlink.h    | 31 +++++++++++++++++++---
 patches/0097-nla_policy_binary_range.cocci |  5 ++++
 2 files changed, 32 insertions(+), 4 deletions(-)
 create mode 100644 patches/0097-nla_policy_binary_range.cocci
diff mbox series

Patch

diff --git a/backport/backport-include/net/netlink.h b/backport/backport-include/net/netlink.h
index ad5882347440..7192153b860c 100644
--- a/backport/backport-include/net/netlink.h
+++ b/backport/backport-include/net/netlink.h
@@ -346,10 +346,33 @@  enum nla_policy_validation {
 }
 #endif /* < 4.20 */
 
-#ifndef NLA_POLICY_MIN_LEN
-#define NLA_POLICY_MIN_LEN(_len) {		\
-	.type = NLA_BINARY			\
+#if LINUX_VERSION_IS_LESS(5,10,0)
+// pre-declare all the minimum lengths in use
+#define MIN_LEN_VALIDATION(n)						\
+static inline								\
+int nla_validate_min_len_##n(const struct nlattr *attr,			\
+			     struct netlink_ext_ack *extack)		\
+{									\
+	if (nla_len(attr) < n)						\
+		return -EINVAL;						\
+	return 0;							\
 }
-#endif
+
+MIN_LEN_VALIDATION(2)
+MIN_LEN_VALIDATION(16)
+MIN_LEN_VALIDATION(42)
+
+// double-expansion to expand _min to the actual value
+#define NLA_POLICY_BINARY_RANGE(_min, _max) _NLA_POLICY_BINARY_RANGE(_min, _max)
+#define _NLA_POLICY_BINARY_RANGE(_min, _max)		\
+{							\
+	.type = NLA_BINARY,				\
+	.len = _max,					\
+	.validation_type = NLA_VALIDATE_FUNCTION,	\
+	.validate = nla_validate_min_len_ ## _min,	\
+}
+#else
+#define NLA_POLICY_BINARY_RANGE(_min, _max) NLA_POLICY_RANGE(NLA_BINARY, _min, _max)
+#endif /* < 5.10 */
 
 #endif /* __BACKPORT_NET_NETLINK_H */
diff --git a/patches/0097-nla_policy_binary_range.cocci b/patches/0097-nla_policy_binary_range.cocci
new file mode 100644
index 000000000000..cb3b8be52b51
--- /dev/null
+++ b/patches/0097-nla_policy_binary_range.cocci
@@ -0,0 +1,5 @@ 
+@@
+expression MIN, MAX;
+@@
+-NLA_POLICY_RANGE(NLA_BINARY, MIN, MAX)
++NLA_POLICY_BINARY_RANGE(MIN, MAX)