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-primax.c | 74 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 74 insertions(+) create mode 100644 drivers/hid/hid-primax.c (limited to 'drivers/hid/hid-primax.c') diff --git a/drivers/hid/hid-primax.c b/drivers/hid/hid-primax.c new file mode 100644 index 000000000..8db054280 --- /dev/null +++ b/drivers/hid/hid-primax.c @@ -0,0 +1,74 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * HID driver for primax and similar keyboards with in-band modifiers + * + * Copyright 2011 Google Inc. All Rights Reserved + * + * Author: + * Terry Lambert + */ + +#include +#include +#include + +#include "hid-ids.h" + +static int px_raw_event(struct hid_device *hid, struct hid_report *report, + u8 *data, int size) +{ + int idx = size; + + switch (report->id) { + case 0: /* keyboard input */ + /* + * Convert in-band modifier key values into out of band + * modifier bits and pull the key strokes from the report. + * Thus a report data set which looked like: + * + * [00][00][E0][30][00][00][00][00] + * (no modifier bits + "Left Shift" key + "1" key) + * + * Would be converted to: + * + * [01][00][00][30][00][00][00][00] + * (Left Shift modifier bit + "1" key) + * + * As long as it's in the size range, the upper level + * drivers don't particularly care if there are in-band + * 0-valued keys, so they don't stop parsing. + */ + while (--idx > 1) { + if (data[idx] < 0xE0 || data[idx] > 0xE7) + continue; + data[0] |= (1 << (data[idx] - 0xE0)); + data[idx] = 0; + } + hid_report_raw_event(hid, HID_INPUT_REPORT, data, size, size, 0); + return 1; + + default: /* unknown report */ + /* Unknown report type; pass upstream */ + hid_info(hid, "unknown report type %d\n", report->id); + break; + } + + return 0; +} + +static const struct hid_device_id px_devices[] = { + { HID_USB_DEVICE(USB_VENDOR_ID_PRIMAX, USB_DEVICE_ID_PRIMAX_KEYBOARD) }, + { } +}; +MODULE_DEVICE_TABLE(hid, px_devices); + +static struct hid_driver px_driver = { + .name = "primax", + .id_table = px_devices, + .raw_event = px_raw_event, +}; +module_hid_driver(px_driver); + +MODULE_AUTHOR("Terry Lambert "); +MODULE_DESCRIPTION("HID driver for primax and similar keyboards with in-band modifiers"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1