selftests/bpf: Reject graph kptr use after RCU unlockgrafted

Add a sleepable verifier test that loads a graph-node local kptr in an
explicit RCU read-side critical section, then passes its node to
bpf_rbtree_remove() after the section ends.

Before the verifier fix, the stale NON_OWN_REF flag makes the node look like
a live borrowed reference and the program is accepted. After the fix, the
pointer is demoted without NON_OWN_REF and the graph kfunc argument is
rejected.

Also exercise a graph kptr loaded while a spin lock provides implicit RCU
protection. The pointer must be invalidated when the lock is released, which
guards the required ordering between non-owning-reference invalidation and
RCU demotion.

Update the existing fault-protected load test state description. The
post-unlock pointer no longer carries NON_OWN_REF, but remains readable
because the load is rewritten to use BPF_PROBE_MEM.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 23 insertions, 0 deletions

diff --git a/include/net/ethoc.h b/include/net/ethoc.h
new file mode 100644
index 000000000..73810f3ca
--- /dev/null
+++ b/include/net/ethoc.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * linux/include/net/ethoc.h
+ *
+ * Copyright (C) 2008-2009 Avionic Design GmbH
+ *
+ * Written by Thierry Reding <thierry.reding@avionic-design.de>
+ */
+
+#ifndef LINUX_NET_ETHOC_H
+#define LINUX_NET_ETHOC_H 1
+
+#include <linux/if.h>
+#include <linux/types.h>
+
+struct ethoc_platform_data {
+	u8 hwaddr[IFHWADDRLEN];
+	s8 phy_id;
+	u32 eth_clkfreq;
+	bool big_endian;
+};
+
+#endif /* !LINUX_NET_ETHOC_H */