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, 35 insertions, 0 deletions

diff --git a/drivers/soc/Kconfig b/drivers/soc/Kconfig
new file mode 100644
index 000000000..a2d65adff
--- /dev/null
+++ b/drivers/soc/Kconfig
@@ -0,0 +1,35 @@
+# SPDX-License-Identifier: GPL-2.0-only
+menu "SOC (System On Chip) specific Drivers"
+
+source "drivers/soc/amlogic/Kconfig"
+source "drivers/soc/apple/Kconfig"
+source "drivers/soc/aspeed/Kconfig"
+source "drivers/soc/atmel/Kconfig"
+source "drivers/soc/bcm/Kconfig"
+source "drivers/soc/canaan/Kconfig"
+source "drivers/soc/cirrus/Kconfig"
+source "drivers/soc/fsl/Kconfig"
+source "drivers/soc/fujitsu/Kconfig"
+source "drivers/soc/hisilicon/Kconfig"
+source "drivers/soc/imx/Kconfig"
+source "drivers/soc/ixp4xx/Kconfig"
+source "drivers/soc/litex/Kconfig"
+source "drivers/soc/loongson/Kconfig"
+source "drivers/soc/mediatek/Kconfig"
+source "drivers/soc/microchip/Kconfig"
+source "drivers/soc/nuvoton/Kconfig"
+source "drivers/soc/pxa/Kconfig"
+source "drivers/soc/qcom/Kconfig"
+source "drivers/soc/renesas/Kconfig"
+source "drivers/soc/rockchip/Kconfig"
+source "drivers/soc/samsung/Kconfig"
+source "drivers/soc/sophgo/Kconfig"
+source "drivers/soc/sunxi/Kconfig"
+source "drivers/soc/tegra/Kconfig"
+source "drivers/soc/ti/Kconfig"
+source "drivers/soc/ux500/Kconfig"
+source "drivers/soc/versatile/Kconfig"
+source "drivers/soc/vt8500/Kconfig"
+source "drivers/soc/xilinx/Kconfig"
+
+endmenu