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/Makefile.defconf | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) create mode 100644 scripts/Makefile.defconf (limited to 'scripts/Makefile.defconf') diff --git a/scripts/Makefile.defconf b/scripts/Makefile.defconf new file mode 100644 index 000000000..a44307f08 --- /dev/null +++ b/scripts/Makefile.defconf @@ -0,0 +1,30 @@ +# SPDX-License-Identifier: GPL-2.0 +# Configuration heplers + +cmd_merge_fragments = \ + $(srctree)/scripts/kconfig/merge_config.sh \ + $4 -m -O $(objtree) $(srctree)/arch/$(SRCARCH)/configs/$2 \ + $(foreach config,$3,$(srctree)/arch/$(SRCARCH)/configs/$(config).config) + +# Creates 'merged defconfigs' +# --------------------------------------------------------------------------- +# Usage: +# $(call merge_into_defconfig,base_config,config_fragment1 config_fragment2 ...) +# +# Input config fragments without '.config' suffix +define merge_into_defconfig + $(call cmd,merge_fragments,$1,$2) + +$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig +endef + + +# Creates 'merged defconfigs without warning about overrides' +# --------------------------------------------------------------------------- +# Usage: +# $(call merge_into_defconfig_override,base_config,config_fragment1 config_fragment2 ...) +# +# Input config fragments without '.config' suffix +define merge_into_defconfig_override + $(call cmd,merge_fragments,$1,$2,-Q) + +$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig +endef -- cgit v1.3.1