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, 36 insertions, 0 deletions

diff --git a/fs/netfs/Makefile b/fs/netfs/Makefile
new file mode 100644
index 000000000..b43188d64
--- /dev/null
+++ b/fs/netfs/Makefile
@@ -0,0 +1,36 @@
+# SPDX-License-Identifier: GPL-2.0
+
+netfs-y := \
+	buffered_read.o \
+	buffered_write.o \
+	direct_read.o \
+	direct_write.o \
+	iterator.o \
+	locking.o \
+	main.o \
+	misc.o \
+	objects.o \
+	read_collect.o \
+	read_pgpriv2.o \
+	read_retry.o \
+	read_single.o \
+	rolling_buffer.o \
+	write_collect.o \
+	write_issue.o \
+	write_retry.o
+
+netfs-$(CONFIG_NETFS_STATS) += stats.o
+
+netfs-$(CONFIG_FSCACHE) += \
+	fscache_cache.o \
+	fscache_cookie.o \
+	fscache_io.o \
+	fscache_main.o \
+	fscache_volume.o
+
+ifeq ($(CONFIG_PROC_FS),y)
+netfs-$(CONFIG_FSCACHE) += fscache_proc.o
+endif
+netfs-$(CONFIG_FSCACHE_STATS) += fscache_stats.o
+
+obj-$(CONFIG_NETFS_SUPPORT) += netfs.o