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, 42 insertions, 0 deletions

diff --git a/sound/soc/codecs/chv3-codec.c b/sound/soc/codecs/chv3-codec.c
new file mode 100644
index 000000000..40020500b
--- /dev/null
+++ b/sound/soc/codecs/chv3-codec.c
@@ -0,0 +1,42 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/module.h>
+#include <sound/soc.h>
+
+static struct snd_soc_dai_driver chv3_codec_dai = {
+	.name = "chv3-codec-hifi",
+	.capture = {
+		.stream_name = "Capture",
+		.channels_min = 8,
+		.channels_max = 8,
+		.rates = SNDRV_PCM_RATE_CONTINUOUS,
+		.formats = SNDRV_PCM_FMTBIT_S32_LE,
+	},
+};
+
+static const struct snd_soc_component_driver soc_component_dev_chv3_codec = {
+};
+
+static int chv3_codec_probe(struct platform_device *pdev)
+{
+	return devm_snd_soc_register_component(&pdev->dev,
+		&soc_component_dev_chv3_codec, &chv3_codec_dai, 1);
+}
+
+static const struct of_device_id chv3_codec_of_match[] = {
+	{ .compatible = "google,chv3-codec", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, chv3_codec_of_match);
+
+static struct platform_driver chv3_codec_platform_driver = {
+	.driver = {
+		.name = "chv3-codec",
+		.of_match_table = chv3_codec_of_match,
+	},
+	.probe = chv3_codec_probe,
+};
+module_platform_driver(chv3_codec_platform_driver);
+
+MODULE_DESCRIPTION("ASoC Chameleon v3 codec driver");
+MODULE_AUTHOR("Pawel Anikiel <pan@semihalf.com>");
+MODULE_LICENSE("GPL");