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-keytouch.c | 51 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+) create mode 100644 drivers/hid/hid-keytouch.c (limited to 'drivers/hid/hid-keytouch.c') diff --git a/drivers/hid/hid-keytouch.c b/drivers/hid/hid-keytouch.c new file mode 100644 index 000000000..b9abd53a5 --- /dev/null +++ b/drivers/hid/hid-keytouch.c @@ -0,0 +1,51 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * HID driver for Keytouch devices not fully compliant with HID standard + * + * Copyright (c) 2011 Jiri Kosina + */ + +/* + */ + +#include +#include +#include + +#include "hid-ids.h" + +/* Replace the broken report descriptor of this device with rather + * a default one */ +static const __u8 keytouch_fixed_rdesc[] = { +0x05, 0x01, 0x09, 0x06, 0xa1, 0x01, 0x05, 0x07, 0x19, 0xe0, 0x29, 0xe7, 0x15, +0x00, 0x25, 0x01, 0x75, 0x01, 0x95, 0x08, 0x81, 0x02, 0x95, 0x01, 0x75, 0x08, +0x81, 0x01, 0x95, 0x03, 0x75, 0x01, 0x05, 0x08, 0x19, 0x01, 0x29, 0x03, 0x91, +0x02, 0x95, 0x05, 0x75, 0x01, 0x91, 0x01, 0x95, 0x06, 0x75, 0x08, 0x15, 0x00, +0x26, 0xff, 0x00, 0x05, 0x07, 0x19, 0x00, 0x2a, 0xff, 0x00, 0x81, 0x00, 0xc0 +}; + +static const __u8 *keytouch_report_fixup(struct hid_device *hdev, __u8 *rdesc, + unsigned int *rsize) +{ + hid_info(hdev, "fixing up Keytouch IEC report descriptor\n"); + + *rsize = sizeof(keytouch_fixed_rdesc); + return keytouch_fixed_rdesc; +} + +static const struct hid_device_id keytouch_devices[] = { + { HID_USB_DEVICE(USB_VENDOR_ID_KEYTOUCH, USB_DEVICE_ID_KEYTOUCH_IEC) }, + { } +}; +MODULE_DEVICE_TABLE(hid, keytouch_devices); + +static struct hid_driver keytouch_driver = { + .name = "keytouch", + .id_table = keytouch_devices, + .report_fixup = keytouch_report_fixup, +}; +module_hid_driver(keytouch_driver); + +MODULE_DESCRIPTION("HID driver for Keytouch devices not fully compliant with HID standard"); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Jiri Kosina"); -- cgit v1.3.1