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/arm64/lib/Makefile | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) create mode 100644 arch/arm64/lib/Makefile (limited to 'arch/arm64/lib/Makefile') diff --git a/arch/arm64/lib/Makefile b/arch/arm64/lib/Makefile new file mode 100644 index 000000000..b33e1ca4a --- /dev/null +++ b/arch/arm64/lib/Makefile @@ -0,0 +1,18 @@ +# SPDX-License-Identifier: GPL-2.0 + +# KCSAN uses udelay for introducing watchpoint delay; avoid recursion. +KCSAN_SANITIZE_delay.o := n + +lib-y := clear_user.o delay.o copy_from_user.o \ + copy_to_user.o copy_page.o \ + clear_page.o csum.o insn.o memchr.o memcpy.o \ + memset.o memcmp.o strcmp.o strncmp.o strlen.o \ + strnlen.o strchr.o strrchr.o tishift.o + +lib-$(CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE) += uaccess_flushcache.o + +obj-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o + +obj-$(CONFIG_ARM64_MTE) += mte.o + +obj-$(CONFIG_KASAN_SW_TAGS) += kasan_sw_tags.o -- cgit v1.3.1