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, 24 insertions, 0 deletions

diff --git a/drivers/mtd/devices/Makefile b/drivers/mtd/devices/Makefile
new file mode 100644
index 000000000..9fe4ce9cf
--- /dev/null
+++ b/drivers/mtd/devices/Makefile
@@ -0,0 +1,24 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# linux/drivers/mtd/devices/Makefile
+#
+
+obj-$(CONFIG_MTD_DOCG3)		+= docg3.o
+obj-$(CONFIG_MTD_SLRAM)		+= slram.o
+obj-$(CONFIG_MTD_PHRAM)		+= phram.o
+obj-$(CONFIG_MTD_PMC551)	+= pmc551.o
+obj-$(CONFIG_MTD_MS02NV)	+= ms02-nv.o
+obj-$(CONFIG_MTD_MTDRAM)	+= mtdram.o
+obj-$(CONFIG_MTD_BLOCK2MTD)	+= block2mtd.o
+obj-$(CONFIG_MTD_DATAFLASH)	+= mtd_dataflash.o
+obj-$(CONFIG_MTD_MCHP23K256)	+= mchp23k256.o
+obj-$(CONFIG_MTD_MCHP48L640)	+= mchp48l640.o
+obj-$(CONFIG_MTD_SPEAR_SMI)	+= spear_smi.o
+obj-$(CONFIG_MTD_SST25L)	+= sst25l.o
+obj-$(CONFIG_MTD_BCM47XXSFLASH)	+= bcm47xxsflash.o
+obj-$(CONFIG_MTD_ST_SPI_FSM)    += st_spi_fsm.o
+obj-$(CONFIG_MTD_POWERNV_FLASH)	+= powernv_flash.o
+obj-$(CONFIG_MTD_INTEL_DG)	+= mtd_intel_dg.o
+
+
+CFLAGS_docg3.o			+= -I$(src)