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, 58 insertions, 0 deletions

diff --git a/include/dt-bindings/clock/aspeed-clock.h b/include/dt-bindings/clock/aspeed-clock.h
new file mode 100644
index 000000000..671e5a476
--- /dev/null
+++ b/include/dt-bindings/clock/aspeed-clock.h
@@ -0,0 +1,58 @@
+/* SPDX-License-Identifier: (GPL-2.0+ OR MIT) */
+
+#ifndef DT_BINDINGS_ASPEED_CLOCK_H
+#define DT_BINDINGS_ASPEED_CLOCK_H
+
+#define ASPEED_CLK_GATE_ECLK		0
+#define ASPEED_CLK_GATE_GCLK		1
+#define ASPEED_CLK_GATE_MCLK		2
+#define ASPEED_CLK_GATE_VCLK		3
+#define ASPEED_CLK_GATE_BCLK		4
+#define ASPEED_CLK_GATE_DCLK		5
+#define ASPEED_CLK_GATE_REFCLK		6
+#define ASPEED_CLK_GATE_USBPORT2CLK	7
+#define ASPEED_CLK_GATE_LCLK		8
+#define ASPEED_CLK_GATE_USBUHCICLK	9
+#define ASPEED_CLK_GATE_D1CLK		10
+#define ASPEED_CLK_GATE_YCLK		11
+#define ASPEED_CLK_GATE_USBPORT1CLK	12
+#define ASPEED_CLK_GATE_UART1CLK	13
+#define ASPEED_CLK_GATE_UART2CLK	14
+#define ASPEED_CLK_GATE_UART5CLK	15
+#define ASPEED_CLK_GATE_ESPICLK		16
+#define ASPEED_CLK_GATE_MAC1CLK		17
+#define ASPEED_CLK_GATE_MAC2CLK		18
+#define ASPEED_CLK_GATE_RSACLK		19
+#define ASPEED_CLK_GATE_UART3CLK	20
+#define ASPEED_CLK_GATE_UART4CLK	21
+#define ASPEED_CLK_GATE_SDCLK		22
+#define ASPEED_CLK_GATE_LHCCLK		23
+#define ASPEED_CLK_HPLL			24
+#define ASPEED_CLK_AHB			25
+#define ASPEED_CLK_APB			26
+#define ASPEED_CLK_UART			27
+#define ASPEED_CLK_SDIO			28
+#define ASPEED_CLK_ECLK			29
+#define ASPEED_CLK_ECLK_MUX		30
+#define ASPEED_CLK_LHCLK		31
+#define ASPEED_CLK_MAC			32
+#define ASPEED_CLK_BCLK			33
+#define ASPEED_CLK_MPLL			34
+#define ASPEED_CLK_24M			35
+#define ASPEED_CLK_MAC1RCLK		36
+#define ASPEED_CLK_MAC2RCLK		37
+
+#define ASPEED_RESET_XDMA		0
+#define ASPEED_RESET_MCTP		1
+#define ASPEED_RESET_ADC		2
+#define ASPEED_RESET_JTAG_MASTER	3
+#define ASPEED_RESET_MIC		4
+#define ASPEED_RESET_PWM		5
+#define ASPEED_RESET_PECI		6
+#define ASPEED_RESET_I2C		7
+#define ASPEED_RESET_AHB		8
+#define ASPEED_RESET_CRT1		9
+#define ASPEED_RESET_HACE		10
+#define ASPEED_RESET_VIDEO		11
+
+#endif