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/hid/hid-semitek.c | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) create mode 100644 drivers/hid/hid-semitek.c (limited to 'drivers/hid/hid-semitek.c') diff --git a/drivers/hid/hid-semitek.c b/drivers/hid/hid-semitek.c new file mode 100644 index 000000000..4fbec5fd8 --- /dev/null +++ b/drivers/hid/hid-semitek.c @@ -0,0 +1,41 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * HID driver for Semitek keyboards + * + * Copyright (c) 2021 Benjamin Moody + */ + +#include +#include +#include + +#include "hid-ids.h" + +static const __u8 *semitek_report_fixup(struct hid_device *hdev, __u8 *rdesc, + unsigned int *rsize) +{ + /* In the report descriptor for interface 2, fix the incorrect + description of report ID 0x04 (the report contains a + bitmask, not an array of keycodes.) */ + if (*rsize == 0xcb && rdesc[0x83] == 0x81 && rdesc[0x84] == 0x00) { + hid_info(hdev, "fixing up Semitek report descriptor\n"); + rdesc[0x84] = 0x02; + } + return rdesc; +} + +static const struct hid_device_id semitek_devices[] = { + { HID_USB_DEVICE(USB_VENDOR_ID_SEMITEK, USB_DEVICE_ID_SEMITEK_KEYBOARD) }, + { } +}; +MODULE_DEVICE_TABLE(hid, semitek_devices); + +static struct hid_driver semitek_driver = { + .name = "semitek", + .id_table = semitek_devices, + .report_fixup = semitek_report_fixup, +}; +module_hid_driver(semitek_driver); + +MODULE_DESCRIPTION("HID driver for Semitek keyboards"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1