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 --- scripts/mod/Makefile | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) create mode 100644 scripts/mod/Makefile (limited to 'scripts/mod/Makefile') diff --git a/scripts/mod/Makefile b/scripts/mod/Makefile new file mode 100644 index 000000000..c729bc936 --- /dev/null +++ b/scripts/mod/Makefile @@ -0,0 +1,27 @@ +# SPDX-License-Identifier: GPL-2.0 +CFLAGS_REMOVE_empty.o += $(CC_FLAGS_LTO) + +hostprogs-always-y += modpost mk_elfconfig +always-y += empty.o + +modpost-objs := modpost.o file2alias.o sumversion.o symsearch.o + +devicetable-offsets-file := devicetable-offsets.h + +$(obj)/$(devicetable-offsets-file): $(obj)/devicetable-offsets.s FORCE + $(call filechk,offsets,__DEVICETABLE_OFFSETS_H__) + +targets += $(devicetable-offsets-file) devicetable-offsets.s + +# dependencies on generated files need to be listed explicitly + +$(obj)/modpost.o $(obj)/file2alias.o $(obj)/sumversion.o $(obj)/symsearch.o: $(obj)/elfconfig.h +$(obj)/file2alias.o: $(obj)/$(devicetable-offsets-file) + +quiet_cmd_elfconfig = MKELF $@ + cmd_elfconfig = $(obj)/mk_elfconfig < $< > $@ + +$(obj)/elfconfig.h: $(obj)/empty.o $(obj)/mk_elfconfig FORCE + $(call if_changed,elfconfig) + +targets += elfconfig.h -- cgit v1.3.1