openrisc: fix arbitrary kernel memory access via or1k_atomic syscallgrafted

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 <ali@iusegentoo.com>
Signed-off-by: Stafford Horne <shorne@gmail.com>

1 files changed, 74 insertions, 0 deletions

diff --git a/include/dt-bindings/clock/pxa-clock.h b/include/dt-bindings/clock/pxa-clock.h
new file mode 100644
index 000000000..ce3d6b6a2
--- /dev/null
+++ b/include/dt-bindings/clock/pxa-clock.h
@@ -0,0 +1,74 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Inspired by original work from pxa2xx-regs.h by Nicolas Pitre
+ * Copyright (C) 2014 Robert Jarzmik
+ */
+
+#ifndef __DT_BINDINGS_CLOCK_PXA2XX_H__
+#define __DT_BINDINGS_CLOCK_PXA2XX_H__
+
+#define CLK_NONE 0
+#define CLK_1WIRE 1
+#define CLK_AC97 2
+#define CLK_AC97CONF 3
+#define CLK_ASSP 4
+#define CLK_BOOT 5
+#define CLK_BTUART 6
+#define CLK_CAMERA 7
+#define CLK_CIR 8
+#define CLK_CORE 9
+#define CLK_DMC 10
+#define CLK_FFUART 11
+#define CLK_FICP 12
+#define CLK_GPIO 13
+#define CLK_HSIO2 14
+#define CLK_HWUART 15
+#define CLK_I2C 16
+#define CLK_I2S 17
+#define CLK_IM 18
+#define CLK_INC 19
+#define CLK_ISC 20
+#define CLK_KEYPAD 21
+#define CLK_LCD 22
+#define CLK_MEMC 23
+#define CLK_MEMSTK 24
+#define CLK_MINI_IM 25
+#define CLK_MINI_LCD 26
+#define CLK_MMC 27
+#define CLK_MMC1 28
+#define CLK_MMC2 29
+#define CLK_MMC3 30
+#define CLK_MSL 31
+#define CLK_MSL0 32
+#define CLK_MVED 33
+#define CLK_NAND 34
+#define CLK_NSSP 35
+#define CLK_OSTIMER 36
+#define CLK_PWM0 37
+#define CLK_PWM1 38
+#define CLK_PWM2 39
+#define CLK_PWM3 40
+#define CLK_PWRI2C 41
+#define CLK_PXA300_GCU 42
+#define CLK_PXA320_GCU 43
+#define CLK_SMC 44
+#define CLK_SSP 45
+#define CLK_SSP1 46
+#define CLK_SSP2 47
+#define CLK_SSP3 48
+#define CLK_SSP4 49
+#define CLK_STUART 50
+#define CLK_TOUCH 51
+#define CLK_TPM 52
+#define CLK_UDC 53
+#define CLK_USB 54
+#define CLK_USB2 55
+#define CLK_USBH 56
+#define CLK_USBHOST 57
+#define CLK_USIM 58
+#define CLK_USIM1 59
+#define CLK_USMI0 60
+#define CLK_OSC32k768 61
+#define CLK_MAX 62
+
+#endif