diff --git a/gpu/command_buffer/service/shared_image/egl_image_backing.cc b/gpu/command_buffer/service/shared_image/egl_image_backing.cc
index d04887c446b6e..8567b76171464 100644
--- a/gpu/command_buffer/service/shared_image/egl_image_backing.cc
+++ b/gpu/command_buffer/service/shared_image/egl_image_backing.cc
@@ -471,6 +471,12 @@ EGLImageBacking::GenEGLImageSiblings(base::span<const uint8_t> pixel_data) {
     AutoLock auto_lock(this);
     create_egl_images = egl_images_.empty();
     if (create_egl_images) {
+      if (!pixel_data.empty()) {
+        // Drain any pre-existing GL errors so we can attribute failures to the
+        // allocation/upload below before deciding whether to SetCleared().
+        while (api->glGetErrorFn() != GL_NO_ERROR) {
+        }
+      }
       for (int plane = 0; plane < num_planes; plane++) {
         gl::ScopedEGLImage egl_image =
             GenEGLImageSibling(pixel_data, service_ids, plane);
@@ -527,7 +533,19 @@ EGLImageBacking::GenEGLImageSiblings(base::span<const uint8_t> pixel_data) {
   // SetCleared() acquires the lock. Hence it is kept outside of previous lock
   // above.
   if (!pixel_data.empty()) {
-    SetCleared();
+    // glTexStorage2D in GenEGLImageSibling() allocates undefined-content
+    // storage on a context without robust-resource-init. If the following
+    // glTexSubImage2D failed (e.g. GL_OUT_OF_MEMORY) the storage is still
+    // uninitialised; do not defeat the IsCleared() gate in that case.
+    GLenum error = api->glGetErrorFn();
+    if (error == GL_NO_ERROR) {
+      SetCleared();
+    } else {
+      LOG(ERROR) << "EGLImageBacking: initial pixel upload failed (GL error 0x"
+                 << std::hex << error
+                 << "); backing will remain uncleared to avoid exposing "
+                    "uninitialised GPU memory";
+    }
   }
 
   std::vector<scoped_refptr<EGLImageBacking::TextureHolder>> texture_holders;
diff --git a/gpu/command_buffer/service/shared_image/gl_texture_image_backing.cc b/gpu/command_buffer/service/shared_image/gl_texture_image_backing.cc
index c3f178bc8a454..993a50a0cf649 100644
--- a/gpu/command_buffer/service/shared_image/gl_texture_image_backing.cc
+++ b/gpu/command_buffer/service/shared_image/gl_texture_image_backing.cc
@@ -501,6 +501,11 @@ void GLTextureImageBacking::InitializeGLTexture(
       "GLSharedImage_" + SharedImageBacking::debug_label();
   int num_planes = format().NumberOfPlanes();
   textures_.reserve(num_planes);
+  // Drain any pre-existing GL errors so we can attribute failures to the
+  // allocation/upload below.
+  gl::GLApi* api = gl::g_current_gl_context;
+  while (api->glGetErrorFn() != GL_NO_ERROR) {
+  }
   for (int plane = 0; plane < num_planes; ++plane) {
     auto plane_format = GLTextureHolder::GetPlaneFormat(format(), plane);
     textures_.emplace_back(plane_format, format().GetPlaneSize(plane, size()),
@@ -511,7 +516,23 @@ void GLTextureImageBacking::InitializeGLTexture(
   }
 
   if (!pixel_data.empty()) {
-    SetCleared();
+    // glTexStorage2D allocates undefined-content storage on the
+    // SharedContextState GL context (robust-resource-init is disabled in
+    // production). The subsequent glTexSubImage2D may fail (e.g.
+    // GL_OUT_OF_MEMORY on the staging upload) leaving the storage
+    // uninitialised. Only mark the backing cleared if no GL error was raised,
+    // so the IsCleared() gate on read access continues to protect
+    // uninitialised GPU memory.
+    GLenum error = api->glGetErrorFn();
+    if (error == GL_NO_ERROR) {
+      SetCleared();
+    } else {
+      LOG(ERROR) << "GLTextureImageBacking: initial pixel upload failed (GL "
+                    "error 0x"
+                 << std::hex << error
+                 << "); backing will remain uncleared to avoid exposing "
+                    "uninitialised GPU memory";
+    }
   }
 }