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/powerpc/configs/security.config | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) create mode 100644 arch/powerpc/configs/security.config (limited to 'arch/powerpc/configs/security.config') diff --git a/arch/powerpc/configs/security.config b/arch/powerpc/configs/security.config new file mode 100644 index 000000000..0d54e29e2 --- /dev/null +++ b/arch/powerpc/configs/security.config @@ -0,0 +1,17 @@ +# Help: Common security options for PowerPC builds + +# This is the equivalent of booting with lockdown=integrity +CONFIG_SECURITY=y +CONFIG_SECURITYFS=y +CONFIG_SECURITY_LOCKDOWN_LSM=y +CONFIG_SECURITY_LOCKDOWN_LSM_EARLY=y +CONFIG_LOCK_DOWN_KERNEL_FORCE_INTEGRITY=y + +# These are some general, reasonably inexpensive hardening options +CONFIG_HARDENED_USERCOPY=y +CONFIG_FORTIFY_SOURCE=y +CONFIG_INIT_ON_ALLOC_DEFAULT_ON=y + +# UBSAN bounds checking is very cheap and good for hardening +CONFIG_UBSAN=y +# CONFIG_UBSAN_MISC is not set -- cgit v1.3.1