Fix memory leaks in case MP4File::ReadBytes() throws an exception.

enzo1982 · May 15, 2023 · c724815 · c724815
1 parent 0f97a87
commit c724815
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Showing 3 changed files with 70 additions and 36 deletions.
diff --git a/src/atom_rtp.cpp b/src/atom_rtp.cpp
@@ -125,12 +125,19 @@ void MP4RtpAtom::ReadHntiType()
 
     // read sdp string, length is implicit in size of atom
     uint64_t size = GetEnd() - m_File.GetPosition();
-    char* data = (char*)MP4Malloc(size + 1);
+    char* data = (char*) MP4Malloc(size + 1);
     ASSERT(data != NULL);
-    m_File.ReadBytes((uint8_t*)data, size);
-    data[size] = '\0';
-    ((MP4StringProperty*)m_pProperties[1])->SetValue(data);
-    MP4Free(data);
+    try {
+        m_File.ReadBytes((uint8_t*) data, size);
+        data[size] = '\0';
+        ((MP4StringProperty*) m_pProperties[1])->SetValue(data);
+        MP4Free(data);
+    }
+    catch (Exception*) {
+        // free memory and rethrow
+        MP4Free(data);
+        throw;
+    }
 }
 
 void MP4RtpAtom::Write()

diff --git a/src/atom_sdp.cpp b/src/atom_sdp.cpp
@@ -36,12 +36,19 @@ void MP4SdpAtom::Read()
 {
     // read sdp string, length is implicit in size of atom
     uint64_t size = GetEnd() - m_File.GetPosition();
-    char* data = (char*)MP4Malloc(size + 1);
+    char* data = (char*) MP4Malloc(size + 1);
     ASSERT(data != NULL);
-    m_File.ReadBytes((uint8_t*)data, size);
-    data[size] = '\0';
-    ((MP4StringProperty*)m_pProperties[0])->SetValue(data);
-    MP4Free(data);
+    try {
+        m_File.ReadBytes((uint8_t*) data, size);
+        data[size] = '\0';
+        ((MP4StringProperty*) m_pProperties[0])->SetValue(data);
+        MP4Free(data);
+    }
+    catch (Exception*) {
+        // free memory and rethrow
+        MP4Free(data);
+        throw;
+    }
 }
 
 void MP4SdpAtom::Write()

diff --git a/src/mp4file_io.cpp b/src/mp4file_io.cpp
@@ -325,19 +325,26 @@ char* MP4File::ReadString()
 {
     uint32_t length = 0;
     uint32_t alloced = 64;
-    char* data = (char*)MP4Malloc(alloced);
-
-    do {
-        if (length == alloced) {
-            data = (char*)MP4Realloc(data, alloced * 2);
-            if (data == NULL) return NULL;
-            alloced *= 2;
-        }
-        ReadBytes((uint8_t*)&data[length], 1);
-        length++;
-    } while (data[length - 1] != 0);
-
-    data = (char*)MP4Realloc(data, length);
+    char* data = (char*) MP4Malloc(alloced);
+    try {
+        do {
+            if (length == alloced) {
+                data = (char*) MP4Realloc(data, alloced * 2);
+                if (data == NULL)
+                    return NULL;
+                alloced *= 2;
+            }
+            ReadBytes((uint8_t*) &data[length], 1);
+            length++;
+        } while (data[length - 1] != 0);
+
+        data = (char*) MP4Realloc(data, length);
+    }
+    catch (Exception*) {
+        // free memory and rethrow
+        MP4Free(data);
+        throw;
+    }
     return data;
 }
 
@@ -384,21 +391,34 @@ char* MP4File::ReadCountedString(uint8_t charSize, bool allowExpandedCount, uint
     }
 
     uint32_t byteLength = charLength * charSize;
-    char* data = (char*)MP4Malloc(byteLength + 1);
-    if (byteLength > 0) {
-        ReadBytes((uint8_t*)data, byteLength);
-    }
-    data[byteLength] = '\0';
-
-    // read padding
-    if (fixedLength) {
-        const uint8_t padsize = fixedLength - byteLength -1U;
-        if( padsize ) {
-            uint8_t* padbuf = (uint8_t*)malloc( padsize );
-            ReadBytes( padbuf, padsize );
-            free( padbuf );
+    char* data = (char*) MP4Malloc(byteLength + 1);
+    try {
+        if (byteLength > 0)
+            ReadBytes((uint8_t*) data, byteLength);
+        data[byteLength] = '\0';
+
+        // read padding
+        if (fixedLength) {
+            const uint8_t padsize = fixedLength - byteLength -1U;
+            if (padsize) {
+                uint8_t* padbuf = (uint8_t*) MP4Malloc(padsize);
+                try {
+                    ReadBytes(padbuf, padsize);
+                    MP4Free(padbuf);
+                }
+                catch (Exception*) {
+                    // free memory and rethrow
+                    MP4Free(padbuf);
+                    throw;
+                }
+            }
         }
     }
+    catch (Exception*) {
+        // free memory and rethrow
+        MP4Free(data);
+        throw;
+    }
 
     return data;
 }