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 --- rust/helpers/device.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) create mode 100644 rust/helpers/device.c (limited to 'rust/helpers/device.c') diff --git a/rust/helpers/device.c b/rust/helpers/device.c new file mode 100644 index 000000000..3be4ee590 --- /dev/null +++ b/rust/helpers/device.c @@ -0,0 +1,32 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include + +__rust_helper int rust_helper_devm_add_action(struct device *dev, + void (*action)(void *), + void *data) +{ + return devm_add_action(dev, action, data); +} + +__rust_helper int rust_helper_devm_add_action_or_reset(struct device *dev, + void (*action)(void *), + void *data) +{ + return devm_add_action_or_reset(dev, action, data); +} + +__rust_helper void *rust_helper_dev_get_drvdata(const struct device *dev) +{ + return dev_get_drvdata(dev); +} + +__rust_helper void rust_helper_dev_set_drvdata(struct device *dev, void *data) +{ + dev_set_drvdata(dev, data); +} + +__rust_helper const char *rust_helper_dev_name(const struct device *dev) +{ + return dev_name(dev); +} -- cgit v1.3.1