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-cherry.c | 72 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 72 insertions(+) create mode 100644 drivers/hid/hid-cherry.c (limited to 'drivers/hid/hid-cherry.c') diff --git a/drivers/hid/hid-cherry.c b/drivers/hid/hid-cherry.c new file mode 100644 index 000000000..a504632fe --- /dev/null +++ b/drivers/hid/hid-cherry.c @@ -0,0 +1,72 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * HID driver for some cherry "special" devices + * + * Copyright (c) 1999 Andreas Gal + * Copyright (c) 2000-2005 Vojtech Pavlik + * Copyright (c) 2005 Michael Haboustak for Concept2, Inc + * Copyright (c) 2006-2007 Jiri Kosina + * Copyright (c) 2008 Jiri Slaby + */ + +/* + */ + +#include +#include +#include + +#include "hid-ids.h" + +/* + * Cherry Cymotion keyboard have an invalid HID report descriptor, + * that needs fixing before we can parse it. + */ +static const __u8 *ch_report_fixup(struct hid_device *hdev, __u8 *rdesc, + unsigned int *rsize) +{ + if (*rsize >= 18 && rdesc[11] == 0x3c && rdesc[12] == 0x02) { + hid_info(hdev, "fixing up Cherry Cymotion report descriptor\n"); + rdesc[11] = rdesc[16] = 0xff; + rdesc[12] = rdesc[17] = 0x03; + } + return rdesc; +} + +#define ch_map_key_clear(c) hid_map_usage_clear(hi, usage, bit, max, \ + EV_KEY, (c)) +static int ch_input_mapping(struct hid_device *hdev, struct hid_input *hi, + struct hid_field *field, struct hid_usage *usage, + unsigned long **bit, int *max) +{ + if ((usage->hid & HID_USAGE_PAGE) != HID_UP_CONSUMER) + return 0; + + switch (usage->hid & HID_USAGE) { + case 0x301: ch_map_key_clear(KEY_PROG1); break; + case 0x302: ch_map_key_clear(KEY_PROG2); break; + case 0x303: ch_map_key_clear(KEY_PROG3); break; + default: + return 0; + } + + return 1; +} + +static const struct hid_device_id ch_devices[] = { + { HID_USB_DEVICE(USB_VENDOR_ID_CHERRY, USB_DEVICE_ID_CHERRY_CYMOTION) }, + { HID_USB_DEVICE(USB_VENDOR_ID_CHERRY, USB_DEVICE_ID_CHERRY_CYMOTION_SOLAR) }, + { } +}; +MODULE_DEVICE_TABLE(hid, ch_devices); + +static struct hid_driver ch_driver = { + .name = "cherry", + .id_table = ch_devices, + .report_fixup = ch_report_fixup, + .input_mapping = ch_input_mapping, +}; +module_hid_driver(ch_driver); + +MODULE_DESCRIPTION("HID driver for some cherry \"special\" devices"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1