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, 18 insertions, 0 deletions

diff --git a/drivers/crypto/caam/dpseci-debugfs.h b/drivers/crypto/caam/dpseci-debugfs.h
new file mode 100644
index 000000000..bc22af7be
--- /dev/null
+++ b/drivers/crypto/caam/dpseci-debugfs.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause) */
+/* Copyright 2019 NXP */
+
+#ifndef DPSECI_DEBUGFS_H
+#define DPSECI_DEBUGFS_H
+
+#include <linux/dcache.h>
+#include "caamalg_qi2.h"
+
+#ifdef CONFIG_DEBUG_FS
+void dpaa2_dpseci_debugfs_init(struct dpaa2_caam_priv *priv);
+void dpaa2_dpseci_debugfs_exit(struct dpaa2_caam_priv *priv);
+#else
+static inline void dpaa2_dpseci_debugfs_init(struct dpaa2_caam_priv *priv) {}
+static inline void dpaa2_dpseci_debugfs_exit(struct dpaa2_caam_priv *priv) {}
+#endif /* CONFIG_DEBUG_FS */
+
+#endif /* DPSECI_DEBUGFS_H */