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, 28 insertions, 0 deletions

diff --git a/sound/drivers/Makefile b/sound/drivers/Makefile
new file mode 100644
index 000000000..a08bdd70e
--- /dev/null
+++ b/sound/drivers/Makefile
@@ -0,0 +1,28 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for ALSA
+# Copyright (c) 2001 by Jaroslav Kysela <perex@perex.cz>
+#
+
+snd-dummy-y := dummy.o
+snd-aloop-y := aloop.o
+snd-mtpav-y := mtpav.o
+snd-mts64-y := mts64.o
+snd-pcmtest-y := pcmtest.o
+snd-portman2x4-y := portman2x4.o
+snd-serial-u16550-y := serial-u16550.o
+snd-serial-generic-y := serial-generic.o
+snd-virmidi-y := virmidi.o
+
+# Toplevel Module Dependency
+obj-$(CONFIG_SND_DUMMY) += snd-dummy.o
+obj-$(CONFIG_SND_ALOOP) += snd-aloop.o
+obj-$(CONFIG_SND_VIRMIDI) += snd-virmidi.o
+obj-$(CONFIG_SND_PCMTEST) += snd-pcmtest.o
+obj-$(CONFIG_SND_SERIAL_U16550) += snd-serial-u16550.o
+obj-$(CONFIG_SND_SERIAL_GENERIC) += snd-serial-generic.o
+obj-$(CONFIG_SND_MTPAV) += snd-mtpav.o
+obj-$(CONFIG_SND_MTS64) += snd-mts64.o
+obj-$(CONFIG_SND_PORTMAN2X4) += snd-portman2x4.o
+
+obj-$(CONFIG_SND) += opl3/ opl4/ mpu401/ vx/ pcsp/