[mono] Copy image data with AssemblyLoadContext.LoadFromStream (#43592)

We don't actually pin the byte array, so it must be copied or it can be overwritten once we run a GC on the LOH.

Fixes https://github.com/dotnet/runtime/issues/43402

Tested manually that it fixes the issue using the associated repro. This isn't really something that lends itself to a test, so that's the best I can do.

diff --git a/src/mono/mono/metadata/appdomain.c b/src/mono/mono/metadata/appdomain.c
index 397045a..a14b98d 100644 (file)
--- a/src/mono/mono/metadata/appdomain.c
+++ b/src/mono/mono/metadata/appdomain.c
@@ -2832,7 +2832,7 @@ mono_alc_load_raw_bytes (MonoAssemblyLoadContext *alc, guint8 *assembly_data, gu
 {
        MonoAssembly *ass = NULL;
        MonoImageOpenStatus status;
-       MonoImage *image = mono_image_open_from_data_internal (alc, (char*)assembly_data, raw_assembly_len, FALSE, NULL, refonly, FALSE, NULL, NULL);
+       MonoImage *image = mono_image_open_from_data_internal (alc, (char*)assembly_data, raw_assembly_len, TRUE, NULL, refonly, FALSE, NULL, NULL);
 
        if (!image) {
                mono_error_set_bad_image_by_name (error, "In memory assembly", "0x%p", assembly_data);