bpf: mark a NULL kfunc argument precisegrafted

check_kfunc_arg() allows bpf_register_is_null() for nullable arguments
w/o marking the underlying scalar register precise. Hence a checkpoint
created on such a path would prune against arbitrary scalar value.

Fixes: 3bda08b63670 ("bpf: Allow NULL buffers in bpf_dynptr_slice(_rw)")
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20260904-register-is-null-precise-fixes-v1-5-0f5a360ff15d@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 46 insertions, 0 deletions

diff --git a/net/sunrpc/sunrpc.h b/net/sunrpc/sunrpc.h
new file mode 100644
index 000000000..e3c6e3b63
--- /dev/null
+++ b/net/sunrpc/sunrpc.h
@@ -0,0 +1,46 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/******************************************************************************
+
+(c) 2008 NetApp.  All Rights Reserved.
+
+
+******************************************************************************/
+
+/*
+ * Functions and macros used internally by RPC
+ */
+
+#ifndef _NET_SUNRPC_SUNRPC_H
+#define _NET_SUNRPC_SUNRPC_H
+
+#include <linux/net.h>
+
+/*
+ * Header for dynamically allocated rpc buffers.
+ */
+struct rpc_buffer {
+	size_t	len;
+	char	data[];
+};
+
+static inline int sock_is_loopback(struct sock *sk)
+{
+	struct dst_entry *dst;
+	int loopback = 0;
+	rcu_read_lock();
+	dst = rcu_dereference(sk->sk_dst_cache);
+	if (dst && dst->dev &&
+	    (dst->dev->features & NETIF_F_LOOPBACK))
+		loopback = 1;
+	rcu_read_unlock();
+	return loopback;
+}
+
+struct svc_serv;
+struct svc_rqst;
+int rpc_clients_notifier_register(void);
+void rpc_clients_notifier_unregister(void);
+void auth_domain_cleanup(void);
+void svc_sock_update_bufs(struct svc_serv *serv);
+enum svc_auth_status svc_authenticate(struct svc_rqst *rqstp);
+#endif /* _NET_SUNRPC_SUNRPC_H */