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 --- drivers/base/container.c | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) create mode 100644 drivers/base/container.c (limited to 'drivers/base/container.c') diff --git a/drivers/base/container.c b/drivers/base/container.c new file mode 100644 index 000000000..f40588ebc --- /dev/null +++ b/drivers/base/container.c @@ -0,0 +1,41 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * System bus type for containers. + * + * Copyright (C) 2013, Intel Corporation + * Author: Rafael J. Wysocki + */ + +#include + +#include "base.h" + +#define CONTAINER_BUS_NAME "container" + +static int trivial_online(struct device *dev) +{ + return 0; +} + +static int container_offline(struct device *dev) +{ + struct container_dev *cdev = to_container_dev(dev); + + return cdev->offline ? cdev->offline(cdev) : 0; +} + +const struct bus_type container_subsys = { + .name = CONTAINER_BUS_NAME, + .dev_name = CONTAINER_BUS_NAME, + .online = trivial_online, + .offline = container_offline, +}; + +void __init container_dev_init(void) +{ + int ret; + + ret = subsys_system_register(&container_subsys, NULL); + if (ret) + pr_err("%s() failed: %d\n", __func__, ret); +} -- cgit v1.3.1