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 --- fs/hostfs/Makefile | 13 +++++++++++++ 1 file changed, 13 insertions(+) create mode 100644 fs/hostfs/Makefile (limited to 'fs/hostfs/Makefile') diff --git a/fs/hostfs/Makefile b/fs/hostfs/Makefile new file mode 100644 index 000000000..16be592e8 --- /dev/null +++ b/fs/hostfs/Makefile @@ -0,0 +1,13 @@ +# +# Copyright (C) 2000 Jeff Dike (jdike@karaya.com) +# Licensed under the GPL +# + +hostfs-objs := hostfs_kern.o + +hostfs-builtin-$(CONFIG_HOSTFS) += hostfs_user.o hostfs_user_exp.o + +obj-y := $(hostfs-builtin-y) $(hostfs-builtin-m) +obj-$(CONFIG_HOSTFS) += hostfs.o + +include $(srctree)/arch/um/scripts/Makefile.rules -- cgit v1.3.1