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, 24 insertions, 0 deletions

diff --git a/include/crypto/blowfish.h b/include/crypto/blowfish.h
new file mode 100644
index 000000000..9b384670b
--- /dev/null
+++ b/include/crypto/blowfish.h
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Common values for blowfish algorithms
+ */
+
+#ifndef _CRYPTO_BLOWFISH_H
+#define _CRYPTO_BLOWFISH_H
+
+#include <linux/types.h>
+#include <linux/crypto.h>
+
+#define BF_BLOCK_SIZE 8
+#define BF_MIN_KEY_SIZE 4
+#define BF_MAX_KEY_SIZE 56
+
+struct bf_ctx {
+	u32 p[18];
+	u32 s[1024];
+};
+
+int blowfish_setkey(struct crypto_tfm *tfm, const u8 *key,
+		    unsigned int key_len);
+
+#endif