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 --- arch/arm/lib/Makefile | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) create mode 100644 arch/arm/lib/Makefile (limited to 'arch/arm/lib/Makefile') diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile new file mode 100644 index 000000000..9295055cd --- /dev/null +++ b/arch/arm/lib/Makefile @@ -0,0 +1,42 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# linux/arch/arm/lib/Makefile +# +# Copyright (C) 1995-2000 Russell King +# + +lib-y := changebit.o csumipv6.o csumpartial.o \ + csumpartialcopy.o csumpartialcopyuser.o clearbit.o \ + delay.o delay-loop.o findbit.o memchr.o memcpy.o \ + memmove.o memset.o setbit.o \ + strchr.o strrchr.o \ + testchangebit.o testclearbit.o testsetbit.o \ + ashldi3.o ashrdi3.o lshrdi3.o muldi3.o \ + ucmpdi2.o lib1funcs.o div64.o \ + io-readsb.o io-writesb.o io-readsl.o io-writesl.o \ + call_with_stack.o bswapsdi2.o + +mmu-y := clear_user.o copy_page.o getuser.o putuser.o \ + copy_from_user.o copy_to_user.o + +ifdef CONFIG_CC_IS_CLANG + lib-y += backtrace-clang.o +else + lib-y += backtrace.o +endif + +# using lib_ here won't override already available weak symbols +obj-$(CONFIG_UACCESS_WITH_MEMCPY) += uaccess_with_memcpy.o + +lib-$(CONFIG_MMU) += $(mmu-y) + +ifeq ($(CONFIG_CPU_32v3),y) + lib-y += io-readsw-armv3.o io-writesw-armv3.o +else + lib-y += io-readsw-armv4.o io-writesw-armv4.o +endif + +$(obj)/csumpartialcopy.o: $(obj)/csumpartialcopygeneric.S +$(obj)/csumpartialcopyuser.o: $(obj)/csumpartialcopygeneric.S + +obj-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o -- cgit v1.3.1