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, 73 insertions, 0 deletions

diff --git a/sound/soc/sof/ipc4-telemetry.h b/sound/soc/sof/ipc4-telemetry.h
new file mode 100644
index 000000000..9298f8acc
--- /dev/null
+++ b/sound/soc/sof/ipc4-telemetry.h
@@ -0,0 +1,73 @@
+/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause) */
+/*
+ * This file is provided under a dual BSD/GPLv2 license.  When using or
+ * redistributing this file, you may do so under either license.
+ *
+ * Copyright(c) 2023 Intel Corporation
+ */
+
+#ifndef __SOUND_SOC_SOF_IPC4_TELEMETRY_H
+#define __SOUND_SOC_SOF_IPC4_TELEMETRY_H
+
+/* Target code */
+enum sof_ipc4_coredump_tgt_code {
+	COREDUMP_TGT_UNKNOWN = 0,
+	COREDUMP_TGT_X86,
+	COREDUMP_TGT_X86_64,
+	COREDUMP_TGT_ARM_CORTEX_M,
+	COREDUMP_TGT_RISC_V,
+	COREDUMP_TGT_XTENSA,
+};
+
+#define COREDUMP_ARCH_HDR_ID 'A'
+#define COREDUMP_HDR_ID0 'Z'
+#define COREDUMP_HDR_ID1 'E'
+
+#define XTENSA_BLOCK_HDR_VER		2
+#define XTENSA_CORE_DUMP_SEPARATOR	0x0DEC0DEB
+#define XTENSA_CORE_AR_REGS_COUNT	16
+#define XTENSA_SOC_INTEL_ADSP		3
+#define XTENSA_TOOL_CHAIN_ZEPHYR	1
+#define XTENSA_TOOL_CHAIN_XCC		2
+
+/* Coredump header */
+struct sof_ipc4_coredump_hdr {
+	/* 'Z', 'E' as identifier of file */
+	char id[2];
+
+	/* Identify the version of the header */
+	u16 hdr_version;
+
+	/* Indicate which target (e.g. architecture or SoC) */
+	u16 tgt_code;
+
+	/* Size of uintptr_t in power of 2. (e.g. 5 for 32-bit, 6 for 64-bit) */
+	u8 ptr_size_bits;
+
+	u8 flag;
+
+	/* Reason for the fatal error */
+	u32 reason;
+} __packed;
+
+/* Architecture-specific block header */
+struct sof_ipc4_coredump_arch_hdr {
+	/* COREDUMP_ARCH_HDR_ID to indicate this is a architecture-specific block */
+	char id;
+
+	/* Identify the version of this block */
+	u16 hdr_version;
+
+	/* Number of bytes following the header */
+	u16 num_bytes;
+} __packed;
+
+struct sof_ipc4_telemetry_slot_data {
+	u32 separator;
+	struct sof_ipc4_coredump_hdr hdr;
+	struct sof_ipc4_coredump_arch_hdr arch_hdr;
+	u32 arch_data[];
+} __packed;
+
+void sof_ipc4_create_exception_debugfs_node(struct snd_sof_dev *sdev);
+#endif