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, 41 insertions, 0 deletions

diff --git a/drivers/media/dvb-frontends/tda10071.h b/drivers/media/dvb-frontends/tda10071.h
new file mode 100644
index 000000000..c282c836f
--- /dev/null
+++ b/drivers/media/dvb-frontends/tda10071.h
@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * NXP TDA10071 + Conexant CX24118A DVB-S/S2 demodulator + tuner driver
+ *
+ * Copyright (C) 2011 Antti Palosaari <crope@iki.fi>
+ */
+
+#ifndef TDA10071_H
+#define TDA10071_H
+
+#include <linux/dvb/frontend.h>
+
+/*
+ * I2C address
+ * 0x05, 0x55,
+ */
+
+/**
+ * struct tda10071_platform_data - Platform data for the tda10071 driver
+ * @clk: Clock frequency.
+ * @i2c_wr_max: Max bytes I2C adapter can write at once.
+ * @ts_mode: TS mode.
+ * @spec_inv: Input spectrum inversion.
+ * @pll_multiplier: PLL multiplier.
+ * @tuner_i2c_addr: CX24118A tuner I2C address (0x14, 0x54, ...).
+ * @get_dvb_frontend: Get DVB frontend.
+ */
+struct tda10071_platform_data {
+	u32 clk;
+	u16 i2c_wr_max;
+#define TDA10071_TS_SERIAL        0
+#define TDA10071_TS_PARALLEL      1
+	u8 ts_mode;
+	bool spec_inv;
+	u8 pll_multiplier;
+	u8 tuner_i2c_addr;
+
+	struct dvb_frontend* (*get_dvb_frontend)(struct i2c_client *);
+};
+
+#endif /* TDA10071_H */