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, 77 insertions, 0 deletions

diff --git a/drivers/media/dvb-frontends/tda10048.h b/drivers/media/dvb-frontends/tda10048.h
new file mode 100644
index 000000000..774fc8957
--- /dev/null
+++ b/drivers/media/dvb-frontends/tda10048.h
@@ -0,0 +1,77 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+    NXP TDA10048HN DVB OFDM demodulator driver
+
+    Copyright (C) 2009 Steven Toth <stoth@kernellabs.com>
+
+
+*/
+
+#ifndef TDA10048_H
+#define TDA10048_H
+
+#include <linux/dvb/frontend.h>
+#include <linux/firmware.h>
+
+struct tda10048_config {
+
+	/* the demodulator's i2c address */
+	u8 demod_address;
+
+	/* serial/parallel output */
+#define TDA10048_PARALLEL_OUTPUT 0
+#define TDA10048_SERIAL_OUTPUT   1
+	u8 output_mode;
+
+#define TDA10048_BULKWRITE_200	200
+#define TDA10048_BULKWRITE_50	50
+	u8 fwbulkwritelen;
+
+	/* Spectral Inversion */
+#define TDA10048_INVERSION_OFF 0
+#define TDA10048_INVERSION_ON  1
+	u8 inversion;
+
+#define TDA10048_IF_3300  3300
+#define TDA10048_IF_3500  3500
+#define TDA10048_IF_3800  3800
+#define TDA10048_IF_4000  4000
+#define TDA10048_IF_4300  4300
+#define TDA10048_IF_4500  4500
+#define TDA10048_IF_4750  4750
+#define TDA10048_IF_5000  5000
+#define TDA10048_IF_36130 36130
+	u16 dtv6_if_freq_khz;
+	u16 dtv7_if_freq_khz;
+	u16 dtv8_if_freq_khz;
+
+#define TDA10048_CLK_4000  4000
+#define TDA10048_CLK_16000 16000
+	u16 clk_freq_khz;
+
+	/* Disable I2C gate access */
+	u8 disable_gate_access;
+
+	bool no_firmware;
+
+	bool set_pll;
+	u8 pll_m;
+	u8 pll_p;
+	u8 pll_n;
+};
+
+#if IS_REACHABLE(CONFIG_DVB_TDA10048)
+extern struct dvb_frontend *tda10048_attach(
+	const struct tda10048_config *config,
+	struct i2c_adapter *i2c);
+#else
+static inline struct dvb_frontend *tda10048_attach(
+	const struct tda10048_config *config,
+	struct i2c_adapter *i2c)
+{
+	printk(KERN_WARNING "%s: driver disabled by Kconfig\n", __func__);
+	return NULL;
+}
+#endif /* CONFIG_DVB_TDA10048 */
+
+#endif /* TDA10048_H */