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-evision.c | 75 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 75 insertions(+) create mode 100644 drivers/hid/hid-evision.c (limited to 'drivers/hid/hid-evision.c') diff --git a/drivers/hid/hid-evision.c b/drivers/hid/hid-evision.c new file mode 100644 index 000000000..3e7f43ab8 --- /dev/null +++ b/drivers/hid/hid-evision.c @@ -0,0 +1,75 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * HID driver for EVision devices + * For now, only ignore bogus consumer reports + * sent after the keyboard has been configured + * + * Copyright (c) 2022 Philippe Valembois + */ + +#include +#include +#include +#include + +#include "hid-ids.h" + +static int evision_input_mapping(struct hid_device *hdev, struct hid_input *hi, + struct hid_field *field, struct hid_usage *usage, + unsigned long **bit, int *max) +{ + /* mapping only applies to USB_DEVICE_ID_EVISION_ICL01 */ + if (hdev->product != USB_DEVICE_ID_EVISION_ICL01) + return 0; + + if ((usage->hid & HID_USAGE_PAGE) != HID_UP_CONSUMER) + return 0; + + /* Ignore key down event */ + if ((usage->hid & HID_USAGE) >> 8 == 0x05) + return -1; + /* Ignore key up event */ + if ((usage->hid & HID_USAGE) >> 8 == 0x06) + return -1; + + switch (usage->hid & HID_USAGE) { + /* Ignore configuration saved event */ + case 0x0401: return -1; + /* Ignore reset event */ + case 0x0402: return -1; + } + return 0; +} + +#define REP_DSC_SIZE 236 +#define USAGE_MAX_INDEX 59 + +static const __u8 *evision_report_fixup(struct hid_device *hdev, __u8 *rdesc, + unsigned int *rsize) +{ + if (hdev->product == USB_DEVICE_ID_EV_TELINK_RECEIVER && + *rsize == REP_DSC_SIZE && rdesc[USAGE_MAX_INDEX] == 0x29 && + rdesc[USAGE_MAX_INDEX + 1] == 3) { + hid_info(hdev, "fixing EVision:TeLink Receiver report descriptor\n"); + rdesc[USAGE_MAX_INDEX + 1] = 5; // change usage max from 3 to 5 + } + return rdesc; +} + +static const struct hid_device_id evision_devices[] = { + { HID_USB_DEVICE(USB_VENDOR_ID_EVISION, USB_DEVICE_ID_EVISION_ICL01) }, + { HID_USB_DEVICE(USB_VENDOR_ID_EVISION, USB_DEVICE_ID_EV_TELINK_RECEIVER) }, + { } +}; +MODULE_DEVICE_TABLE(hid, evision_devices); + +static struct hid_driver evision_driver = { + .name = "evision", + .id_table = evision_devices, + .input_mapping = evision_input_mapping, + .report_fixup = evision_report_fixup, +}; +module_hid_driver(evision_driver); + +MODULE_DESCRIPTION("HID driver for EVision devices"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1