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/usb/common/led.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) create mode 100644 drivers/usb/common/led.c (limited to 'drivers/usb/common/led.c') diff --git a/drivers/usb/common/led.c b/drivers/usb/common/led.c new file mode 100644 index 000000000..1de18d90b --- /dev/null +++ b/drivers/usb/common/led.c @@ -0,0 +1,48 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * LED Triggers for USB Activity + * + * Copyright 2014 Michal Sojka + */ + +#include +#include +#include +#include +#include +#include "common.h" + +#define BLINK_DELAY 30 + +DEFINE_LED_TRIGGER(ledtrig_usb_gadget); +DEFINE_LED_TRIGGER(ledtrig_usb_host); + +void usb_led_activity(enum usb_led_event ev) +{ + struct led_trigger *trig = NULL; + + switch (ev) { + case USB_LED_EVENT_GADGET: + trig = ledtrig_usb_gadget; + break; + case USB_LED_EVENT_HOST: + trig = ledtrig_usb_host; + break; + } + /* led_trigger_blink_oneshot() handles trig == NULL gracefully */ + led_trigger_blink_oneshot(trig, BLINK_DELAY, BLINK_DELAY, 0); +} +EXPORT_SYMBOL_GPL(usb_led_activity); + + +void __init ledtrig_usb_init(void) +{ + led_trigger_register_simple("usb-gadget", &ledtrig_usb_gadget); + led_trigger_register_simple("usb-host", &ledtrig_usb_host); +} + +void __exit ledtrig_usb_exit(void) +{ + led_trigger_unregister_simple(ledtrig_usb_gadget); + led_trigger_unregister_simple(ledtrig_usb_host); +} -- cgit v1.3.1