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, 53 insertions, 0 deletions

diff --git a/sound/soc/sof/trace.c b/sound/soc/sof/trace.c
new file mode 100644
index 000000000..fe6c67c01
--- /dev/null
+++ b/sound/soc/sof/trace.c
@@ -0,0 +1,53 @@
+// SPDX-License-Identifier: GPL-2.0-only
+//
+// Copyright(c) 2022 Intel Corporation
+
+#include "sof-priv.h"
+
+int sof_fw_trace_init(struct snd_sof_dev *sdev)
+{
+	const struct sof_ipc_fw_tracing_ops *fw_tracing = sof_ipc_get_ops(sdev, fw_tracing);
+
+	if (!fw_tracing) {
+		dev_info(sdev->dev, "Firmware tracing is not available\n");
+		sdev->fw_trace_is_supported = false;
+
+		return 0;
+	}
+
+	return fw_tracing->init(sdev);
+}
+
+void sof_fw_trace_free(struct snd_sof_dev *sdev)
+{
+	if (!sdev->fw_trace_is_supported)
+		return;
+
+	if (sdev->ipc->ops->fw_tracing->free)
+		sdev->ipc->ops->fw_tracing->free(sdev);
+}
+
+void sof_fw_trace_fw_crashed(struct snd_sof_dev *sdev)
+{
+	if (!sdev->fw_trace_is_supported)
+		return;
+
+	if (sdev->ipc->ops->fw_tracing->fw_crashed)
+		sdev->ipc->ops->fw_tracing->fw_crashed(sdev);
+}
+
+void sof_fw_trace_suspend(struct snd_sof_dev *sdev, pm_message_t pm_state)
+{
+	if (!sdev->fw_trace_is_supported)
+		return;
+
+	sdev->ipc->ops->fw_tracing->suspend(sdev, pm_state);
+}
+
+int sof_fw_trace_resume(struct snd_sof_dev *sdev)
+{
+	if (!sdev->fw_trace_is_supported)
+		return 0;
+
+	return sdev->ipc->ops->fw_tracing->resume(sdev);
+}