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, 32 insertions, 0 deletions

diff --git a/drivers/net/phy/phylib-internal.h b/drivers/net/phy/phylib-internal.h
new file mode 100644
index 000000000..664ed7faa
--- /dev/null
+++ b/drivers/net/phy/phylib-internal.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * phylib-internal header
+ */
+
+#ifndef __PHYLIB_INTERNAL_H
+#define __PHYLIB_INTERNAL_H
+
+struct mdio_device;
+struct phy_device;
+
+extern const struct bus_type mdio_bus_type;
+extern const struct class mdio_bus_class;
+
+/*
+ * phy_supported_speeds - return all speeds currently supported by a PHY device
+ */
+unsigned int phy_supported_speeds(struct phy_device *phy,
+				  unsigned int *speeds,
+				  unsigned int size);
+void of_set_phy_supported(struct phy_device *phydev);
+void of_set_phy_eee_broken(struct phy_device *phydev);
+void of_set_phy_timing_role(struct phy_device *phydev);
+int phy_speed_down_core(struct phy_device *phydev);
+void phy_check_downshift(struct phy_device *phydev);
+
+int mdiobus_register_device(struct mdio_device *mdiodev);
+int mdiobus_unregister_device(struct mdio_device *mdiodev);
+
+int genphy_c45_read_eee_adv(struct phy_device *phydev, unsigned long *adv);
+
+#endif /* __PHYLIB_INTERNAL_H */