From 78004e9a87f240df03e2f73120d291763c32e0a7 Mon Sep 17 00:00:00 2001 From: Ali Ahmet Memis Date: Fri, 21 Aug 2026 01:45:27 +0000 Subject: openrisc: fix arbitrary kernel memory access via or1k_atomic syscall sys_or1k_atomic() (syscall 244 in the "or1k" ABI) takes two user pointers, v1 and v2, and swaps the words they point to in hand-written assembly. l.lwz r29,0(r4) l.lwz r27,0(r5) l.sw 0(r4),r27 l.sw 0(r5),r29 The pointers are not checked with access_ok(). The four memory accesses also have no exception table entries. A caller passes a kernel address as either pointer, and the syscall reads from and writes to it directly. This gives an unprivileged process a kernel read/write primitive. It overwrites kernel data such as the sys_call_table, gaining code execution in kernel context. Check both pointers before entering the critical section. Add fixups for the four memory accesses so faults on valid but unmapped user addresses return -EFAULT. [shorne@gmail.com: fix comment style] Fixes: 9d02a4283e9c ("OpenRISC: Boot code") Cc: stable@vger.kernel.org Signed-off-by: Ali Ahmet Memis Signed-off-by: Stafford Horne --- drivers/hid/hid-speedlink.c | 79 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 79 insertions(+) create mode 100644 drivers/hid/hid-speedlink.c (limited to 'drivers/hid/hid-speedlink.c') diff --git a/drivers/hid/hid-speedlink.c b/drivers/hid/hid-speedlink.c new file mode 100644 index 000000000..22ee078c4 --- /dev/null +++ b/drivers/hid/hid-speedlink.c @@ -0,0 +1,79 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * HID driver for Speedlink Vicious and Divine Cezanne (USB mouse). + * Fixes "jumpy" cursor and removes nonexistent keyboard LEDS from + * the HID descriptor. + * + * Copyright (c) 2011, 2013 Stefan Kriwanek + */ + +/* + */ + +#include +#include +#include + +#include "hid-ids.h" + +static const struct hid_device_id speedlink_devices[] = { + { HID_USB_DEVICE(USB_VENDOR_ID_X_TENSIONS, USB_DEVICE_ID_SPEEDLINK_VAD_CEZANNE)}, + { } +}; + +static int speedlink_input_mapping(struct hid_device *hdev, + struct hid_input *hi, + struct hid_field *field, struct hid_usage *usage, + unsigned long **bit, int *max) +{ + /* + * The Cezanne mouse has a second "keyboard" USB endpoint for it is + * able to map keyboard events to the button presses. + * It sends a standard keyboard report descriptor, though, whose + * LEDs we ignore. + */ + switch (usage->hid & HID_USAGE_PAGE) { + case HID_UP_LED: + return -1; + } + return 0; +} + +static int speedlink_event(struct hid_device *hdev, struct hid_field *field, + struct hid_usage *usage, __s32 value) +{ + /* No other conditions due to usage_table. */ + + /* This fixes the "jumpy" cursor occuring due to invalid events sent + * by the device. Some devices only send them with value==+256, others + * don't. However, catching abs(value)>=256 is restrictive enough not + * to interfere with devices that were bug-free (has been tested). + */ + if (abs(value) >= 256) + return 1; + /* Drop useless distance 0 events (on button clicks etc.) as well */ + if (value == 0) + return 1; + + return 0; +} + +MODULE_DEVICE_TABLE(hid, speedlink_devices); + +static const struct hid_usage_id speedlink_grabbed_usages[] = { + { HID_GD_X, EV_REL, 0 }, + { HID_GD_Y, EV_REL, 1 }, + { HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1} +}; + +static struct hid_driver speedlink_driver = { + .name = "speedlink", + .id_table = speedlink_devices, + .usage_table = speedlink_grabbed_usages, + .input_mapping = speedlink_input_mapping, + .event = speedlink_event, +}; +module_hid_driver(speedlink_driver); + +MODULE_DESCRIPTION("HID driver for Speedlink Vicious and Divine Cezanne (USB mouse)"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1