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, 17 insertions, 0 deletions

diff --git a/drivers/mtd/parsers/Makefile b/drivers/mtd/parsers/Makefile
new file mode 100644
index 000000000..9b00c62b8
--- /dev/null
+++ b/drivers/mtd/parsers/Makefile
@@ -0,0 +1,17 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_MTD_BCM47XX_PARTS)		+= bcm47xxpart.o
+obj-$(CONFIG_MTD_BCM63XX_PARTS)		+= bcm63xxpart.o
+obj-$(CONFIG_MTD_BRCM_U_BOOT)		+= brcm_u-boot.o
+obj-$(CONFIG_MTD_CMDLINE_PARTS)		+= cmdlinepart.o
+obj-$(CONFIG_MTD_OF_PARTS)		+= ofpart.o
+ofpart-y				+= ofpart_core.o
+ofpart-$(CONFIG_MTD_OF_PARTS_BCM4908)	+= ofpart_bcm4908.o
+ofpart-$(CONFIG_MTD_OF_PARTS_LINKSYS_NS)+= ofpart_linksys_ns.o
+obj-$(CONFIG_MTD_PARSER_IMAGETAG)	+= parser_imagetag.o
+obj-$(CONFIG_MTD_AFS_PARTS)		+= afs.o
+obj-$(CONFIG_MTD_PARSER_TPLINK_SAFELOADER)	+= tplink_safeloader.o
+obj-$(CONFIG_MTD_PARSER_TRX)		+= parser_trx.o
+obj-$(CONFIG_MTD_SERCOMM_PARTS)		+= scpart.o
+obj-$(CONFIG_MTD_SHARPSL_PARTS)		+= sharpslpart.o
+obj-$(CONFIG_MTD_REDBOOT_PARTS)		+= redboot.o
+obj-$(CONFIG_MTD_QCOMSMEM_PARTS)	+= qcomsmempart.o