From cf4c78b9c825f61ff3ee83eff88442a149ae01d9 Mon Sep 17 00:00:00 2001
From: gdkchan <gab.dark.100@gmail.com>
Date: Mon, 12 Jun 2023 21:12:06 -0300
Subject: [PATCH] Make LM skip instead of crashing for invalid messages (#5290)

---
 src/Ryujinx.Common/Memory/SpanReader.cs       | 18 ++++++++
 .../LogManager/Ipc/LmLogger.cs                | 45 +++++++++++++------
 2 files changed, 49 insertions(+), 14 deletions(-)

diff --git a/src/Ryujinx.Common/Memory/SpanReader.cs b/src/Ryujinx.Common/Memory/SpanReader.cs
index 673932d0..9a1a0a3f 100644
--- a/src/Ryujinx.Common/Memory/SpanReader.cs
+++ b/src/Ryujinx.Common/Memory/SpanReader.cs
@@ -24,6 +24,24 @@ namespace Ryujinx.Common.Memory
             return value;
         }
 
+        public bool TryRead<T>(out T value) where T : unmanaged
+        {
+            int valueSize = Unsafe.SizeOf<T>();
+
+            if (valueSize > _input.Length)
+            {
+                value = default;
+
+                return false;
+            }
+
+            value = MemoryMarshal.Cast<byte, T>(_input)[0];
+
+            _input = _input.Slice(valueSize);
+
+            return true;
+        }
+
         public ReadOnlySpan<byte> GetSpan(int size)
         {
             ReadOnlySpan<byte> data = _input.Slice(0, size);
diff --git a/src/Ryujinx.Horizon/LogManager/Ipc/LmLogger.cs b/src/Ryujinx.Horizon/LogManager/Ipc/LmLogger.cs
index e930bdd7..88dddef5 100644
--- a/src/Ryujinx.Horizon/LogManager/Ipc/LmLogger.cs
+++ b/src/Ryujinx.Horizon/LogManager/Ipc/LmLogger.cs
@@ -17,7 +17,7 @@ namespace Ryujinx.Horizon.LogManager.Ipc
         private const int MessageLengthLimit = 5000;
 
         private readonly LogService _log;
-        private readonly ulong      _pid;
+        private readonly ulong _pid;
 
         private LogPacket _logPacket;
 
@@ -74,8 +74,12 @@ namespace Ryujinx.Horizon.LogManager.Ipc
 
         private bool LogImpl(ReadOnlySpan<byte> message)
         {
-            SpanReader      reader = new(message);
-            LogPacketHeader header = reader.Read<LogPacketHeader>();
+            SpanReader reader = new(message);
+
+            if (!reader.TryRead(out LogPacketHeader header))
+            {
+                return true;
+            }
 
             bool isHeadPacket = (header.Flags & LogPacketFlags.IsHead) != 0;
             bool isTailPacket = (header.Flags & LogPacketFlags.IsTail) != 0;
@@ -84,8 +88,10 @@ namespace Ryujinx.Horizon.LogManager.Ipc
 
             while (reader.Length > 0)
             {
-                int type = ReadUleb128(ref reader);
-                int size = ReadUleb128(ref reader);
+                if (!TryReadUleb128(ref reader, out int type) || !TryReadUleb128(ref reader, out int size))
+                {
+                    return true;
+                }
 
                 LogDataChunkKey key = (LogDataChunkKey)type;
 
@@ -101,15 +107,24 @@ namespace Ryujinx.Horizon.LogManager.Ipc
                 }
                 else if (key == LogDataChunkKey.Line)
                 {
-                    _logPacket.Line = reader.Read<int>();
+                    if (!reader.TryRead<int>(out _logPacket.Line))
+                    {
+                        return true;
+                    }
                 }
                 else if (key == LogDataChunkKey.DropCount)
                 {
-                    _logPacket.DropCount = reader.Read<long>();
+                    if (!reader.TryRead<long>(out _logPacket.DropCount))
+                    {
+                        return true;
+                    }
                 }
                 else if (key == LogDataChunkKey.Time)
                 {
-                    _logPacket.Time = reader.Read<long>();
+                    if (!reader.TryRead<long>(out _logPacket.Time))
+                    {
+                        return true;
+                    }
                 }
                 else if (key == LogDataChunkKey.Message)
                 {
@@ -154,23 +169,25 @@ namespace Ryujinx.Horizon.LogManager.Ipc
             return isTailPacket;
         }
 
-        private static int ReadUleb128(ref SpanReader reader)
+        private static bool TryReadUleb128(ref SpanReader reader, out int result)
         {
-            int result = 0;
-            int count  = 0;
-
+            result = 0;
+            int count = 0;
             byte encoded;
 
             do
             {
-                encoded = reader.Read<byte>();
+                if (!reader.TryRead<byte>(out encoded))
+                {
+                    return false;
+                }
 
                 result += (encoded & 0x7F) << (7 * count);
 
                 count++;
             } while ((encoded & 0x80) != 0);
 
-            return result;
+            return true;
         }
     }
 }
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