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, 105 insertions, 0 deletions

diff --git a/sound/soc/soc-devres.c b/sound/soc/soc-devres.c
new file mode 100644
index 000000000..718165ba8
--- /dev/null
+++ b/sound/soc/soc-devres.c
@@ -0,0 +1,105 @@
+// SPDX-License-Identifier: GPL-2.0+
+//
+// soc-devres.c  --  ALSA SoC Audio Layer devres functions
+//
+// Copyright (C) 2013 Linaro Ltd
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <sound/soc.h>
+#include <sound/dmaengine_pcm.h>
+
+static void devm_component_release(struct device *dev, void *res)
+{
+	const struct snd_soc_component_driver **cmpnt_drv = res;
+
+	snd_soc_unregister_component_by_driver(dev, *cmpnt_drv);
+}
+
+/**
+ * devm_snd_soc_register_component - resource managed component registration
+ * @dev: Device used to manage component
+ * @cmpnt_drv: Component driver
+ * @dai_drv: DAI driver
+ * @num_dai: Number of DAIs to register
+ *
+ * Register a component with automatic unregistration when the device is
+ * unregistered.
+ */
+int devm_snd_soc_register_component(struct device *dev,
+			 const struct snd_soc_component_driver *cmpnt_drv,
+			 struct snd_soc_dai_driver *dai_drv, int num_dai)
+{
+	const struct snd_soc_component_driver **ptr;
+	int ret;
+
+	ptr = devres_alloc(devm_component_release, sizeof(*ptr), GFP_KERNEL);
+	if (!ptr)
+		return -ENOMEM;
+
+	ret = snd_soc_register_component(dev, cmpnt_drv, dai_drv, num_dai);
+	if (ret == 0) {
+		*ptr = cmpnt_drv;
+		devres_add(dev, ptr);
+	} else {
+		devres_free(ptr);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(devm_snd_soc_register_component);
+
+/**
+ * devm_snd_soc_register_card - resource managed card registration
+ * @dev: Device used to manage card
+ * @card: Card to register
+ *
+ * Register a card with automatic unregistration when the device is
+ * unregistered.
+ */
+int devm_snd_soc_register_card(struct device *dev, struct snd_soc_card *card)
+{
+	card->devres_dev = dev;
+	return snd_soc_register_card(card);
+}
+EXPORT_SYMBOL_GPL(devm_snd_soc_register_card);
+
+#ifdef CONFIG_SND_SOC_GENERIC_DMAENGINE_PCM
+
+static void devm_dmaengine_pcm_release(struct device *dev, void *res)
+{
+	snd_dmaengine_pcm_unregister(*(struct device **)res);
+}
+
+/**
+ * devm_snd_dmaengine_pcm_register - resource managed dmaengine PCM registration
+ * @dev: The parent device for the PCM device
+ * @config: Platform specific PCM configuration
+ * @flags: Platform specific quirks
+ *
+ * Register a dmaengine based PCM device with automatic unregistration when the
+ * device is unregistered.
+ */
+int devm_snd_dmaengine_pcm_register(struct device *dev,
+	const struct snd_dmaengine_pcm_config *config, unsigned int flags)
+{
+	struct device **ptr;
+	int ret;
+
+	ptr = devres_alloc(devm_dmaengine_pcm_release, sizeof(*ptr), GFP_KERNEL);
+	if (!ptr)
+		return -ENOMEM;
+
+	ret = snd_dmaengine_pcm_register(dev, config, flags);
+	if (ret == 0) {
+		*ptr = dev;
+		devres_add(dev, ptr);
+	} else {
+		devres_free(ptr);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(devm_snd_dmaengine_pcm_register);
+
+#endif