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, 20 insertions, 0 deletions

diff --git a/include/media/jpeg.h b/include/media/jpeg.h
new file mode 100644
index 000000000..a01e142e9
--- /dev/null
+++ b/include/media/jpeg.h
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _MEDIA_JPEG_H_
+#define _MEDIA_JPEG_H_
+
+/* JPEG markers */
+#define JPEG_MARKER_TEM		0x01
+#define JPEG_MARKER_SOF0	0xc0
+#define JPEG_MARKER_DHT		0xc4
+#define JPEG_MARKER_RST		0xd0
+#define JPEG_MARKER_SOI		0xd8
+#define JPEG_MARKER_EOI		0xd9
+#define JPEG_MARKER_SOS		0xda
+#define JPEG_MARKER_DQT		0xdb
+#define JPEG_MARKER_DRI		0xdd
+#define JPEG_MARKER_DHP		0xde
+#define JPEG_MARKER_APP0	0xe0
+#define JPEG_MARKER_COM		0xfe
+
+#endif /* _MEDIA_JPEG_H_ */