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, 33 insertions, 0 deletions

diff --git a/drivers/hid/intel-ish-hid/Kconfig b/drivers/hid/intel-ish-hid/Kconfig
new file mode 100644
index 000000000..568c86887
--- /dev/null
+++ b/drivers/hid/intel-ish-hid/Kconfig
@@ -0,0 +1,33 @@
+# SPDX-License-Identifier: GPL-2.0-only
+menu "Intel ISH HID support"
+	depends on (X86_64 || COMPILE_TEST) && PCI
+
+config INTEL_ISH_HID
+	tristate "Intel Integrated Sensor Hub"
+	default n
+	depends on X86
+	help
+	  The Integrated Sensor Hub (ISH) enables the ability to offload
+	  sensor polling and algorithm processing to a dedicated low power
+	  processor in the chipset. This allows the core processor to go into
+	  low power modes more often, resulting in the increased battery life.
+	  The current processors that support ISH are: Cherrytrail, Skylake,
+	  Broxton and Kaby Lake.
+
+	  Say Y here if you want to support Intel ISH. If unsure, say N.
+
+config INTEL_ISH_FIRMWARE_DOWNLOADER
+	tristate "Host Firmware Load feature for Intel ISH"
+	depends on INTEL_ISH_HID
+	depends on X86
+	help
+	  The Integrated Sensor Hub (ISH) enables the kernel to offload
+	  sensor polling and algorithm processing to a dedicated low power
+	  processor in the chipset.
+
+	  The Host Firmware Load feature adds support to load the ISH
+	  firmware from host file system at boot.
+
+	  Say M here if you want to support Host Firmware Loading feature
+	  for Intel ISH. If unsure, say N.
+endmenu