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, 29 insertions, 0 deletions

diff --git a/sound/isa/Makefile b/sound/isa/Makefile
new file mode 100644
index 000000000..2135d68a1
--- /dev/null
+++ b/sound/isa/Makefile
@@ -0,0 +1,29 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for ALSA
+# Copyright (c) 2001 by Jaroslav Kysela <perex@perex.cz>
+#
+
+snd-adlib-y := adlib.o
+snd-als100-y := als100.o
+snd-azt2320-y := azt2320.o
+snd-cmi8328-y := cmi8328.o
+snd-cmi8330-y := cmi8330.o
+snd-es18xx-y := es18xx.o
+snd-opl3sa2-y := opl3sa2.o
+snd-sc6000-y := sc6000.o
+snd-sscape-y := sscape.o
+
+# Toplevel Module Dependency
+obj-$(CONFIG_SND_ADLIB) += snd-adlib.o
+obj-$(CONFIG_SND_ALS100) += snd-als100.o
+obj-$(CONFIG_SND_AZT2320) += snd-azt2320.o
+obj-$(CONFIG_SND_CMI8328) += snd-cmi8328.o
+obj-$(CONFIG_SND_CMI8330) += snd-cmi8330.o
+obj-$(CONFIG_SND_ES18XX) += snd-es18xx.o
+obj-$(CONFIG_SND_OPL3SA2) += snd-opl3sa2.o
+obj-$(CONFIG_SND_SC6000) += snd-sc6000.o
+obj-$(CONFIG_SND_SSCAPE) += snd-sscape.o
+
+obj-$(CONFIG_SND) += ad1816a/ ad1848/ cs423x/ es1688/ galaxy/ gus/ msnd/ opti9xx/ \
+		     sb/ wavefront/ wss/