From 6668ed271eaefaa63e686bdfbedaeb7b8e492722 Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Fri, 4 Sep 2026 10:43:19 +0200 Subject: selftests/bpf: Reject graph kptr use after RCU unlock 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 Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- tools/testing/rbtree/Makefile | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) create mode 100644 tools/testing/rbtree/Makefile (limited to 'tools/testing/rbtree/Makefile') diff --git a/tools/testing/rbtree/Makefile b/tools/testing/rbtree/Makefile new file mode 100644 index 000000000..d7bbae2af --- /dev/null +++ b/tools/testing/rbtree/Makefile @@ -0,0 +1,33 @@ +# SPDX-License-Identifier: GPL-2.0 + +.PHONY: clean + +TARGETS = rbtree_test interval_tree_test +OFILES = $(SHARED_OFILES) rbtree-shim.o interval_tree-shim.o maple-shim.o +DEPS = ../../../include/linux/rbtree.h \ + ../../../include/linux/rbtree_types.h \ + ../../../include/linux/rbtree_augmented.h \ + ../../../include/linux/interval_tree.h \ + ../../../include/linux/interval_tree_generic.h \ + ../../../lib/rbtree.c \ + ../../../lib/interval_tree.c + +targets: $(TARGETS) + +include ../shared/shared.mk + +ifeq ($(DEBUG), 1) + CFLAGS += -g +endif + +$(TARGETS): $(OFILES) + +rbtree-shim.o: $(DEPS) +rbtree_test.o: ../../../lib/rbtree_test.c +interval_tree-shim.o: $(DEPS) +interval_tree-shim.o: CFLAGS += -DCONFIG_INTERVAL_TREE_SPAN_ITER +interval_tree_test.o: ../../../lib/interval_tree_test.c +interval_tree_test.o: CFLAGS += -DCONFIG_INTERVAL_TREE_SPAN_ITER + +clean: + $(RM) $(TARGETS) *.o radix-tree.c idr.c generated/* -- cgit v1.3.1