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/misc/cardreader/Kconfig b/drivers/misc/cardreader/Kconfig
new file mode 100644
index 000000000..a70700f0e
--- /dev/null
+++ b/drivers/misc/cardreader/Kconfig
@@ -0,0 +1,33 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config MISC_ALCOR_PCI
+	tristate "Alcor Micro/Alcor Link PCI-E card reader"
+	depends on PCI
+	select MFD_CORE
+	help
+	  This supports for Alcor Micro PCI-Express card reader including au6601,
+	  au6621.
+	  Alcor Micro card readers support access to many types of memory cards,
+	  such as Memory Stick, Memory Stick Pro, Secure Digital and
+	  MultiMediaCard.
+
+config MISC_RTSX_PCI
+	tristate "Realtek PCI-E card reader"
+	depends on PCI
+	select MFD_CORE
+	help
+	  This supports for Realtek PCI-Express card reader including rts5209,
+	  rts5227, rts5228, rts522A, rts5229, rts5249, rts524A, rts525A, rtl8411,
+	  rts5260, rts5261, rts5264.
+	  Realtek card readers support access to many types of memory cards,
+	  such as Memory Stick, Memory Stick Pro, Secure Digital and
+	  MultiMediaCard.
+
+config MISC_RTSX_USB
+	tristate "Realtek USB card reader"
+	depends on USB
+	select MFD_CORE
+	help
+	  Select this option to get support for Realtek USB 2.0 card readers
+	  including RTS5129, RTS5139, RTS5179 and RTS5170.
+	  Realtek card reader supports access to many types of memory cards,
+	  such as Memory Stick Pro, Secure Digital and MultiMediaCard.