[PATCH 1/5] d3d11: Validate offsets and sizes in parse_dxbc() (AFL).

[Henri Verbeet]

Signed-off-by: Henri Verbeet <hverbeet at codeweavers.com>
---
 dlls/d3d11/d3d11_private.h |  5 +++++
 dlls/d3d11/utils.c         | 12 ++++++++++++
 2 files changed, 17 insertions(+)

diff --git a/dlls/d3d11/d3d11_private.h b/dlls/d3d11/d3d11_private.h
index c52e3e4..41fd89d 100644
--- a/dlls/d3d11/d3d11_private.h
+++ b/dlls/d3d11/d3d11_private.h
@@ -85,6 +85,11 @@ static inline void read_dword(const char **ptr, DWORD *d)
     *ptr += sizeof(*d);
 }
 
+static inline BOOL require_space(size_t offset, size_t size, size_t data_size)
+{
+    return data_size - offset >= size;
+}
+
 void skip_dword_unknown(const char **ptr, unsigned int count) DECLSPEC_HIDDEN;
 
 HRESULT parse_dxbc(const char *data, SIZE_T data_size,
diff --git a/dlls/d3d11/utils.c b/dlls/d3d11/utils.c
index 6473722..25e22f9 100644
--- a/dlls/d3d11/utils.c
+++ b/dlls/d3d11/utils.c
@@ -751,11 +751,23 @@ HRESULT parse_dxbc(const char *data, SIZE_T data_size,
         read_dword(&ptr, &chunk_offset);
         TRACE("chunk %u at offset %#x\n", i, chunk_offset);
 
+        if (chunk_offset >= data_size || !require_space(chunk_offset, 2 * sizeof(DWORD), data_size))
+        {
+            WARN("Invalid chunk offset %#x (data size %#lx).\n", chunk_offset, data_size);
+            return E_FAIL;
+        }
+
         chunk_ptr = data + chunk_offset;
 
         read_dword(&chunk_ptr, &chunk_tag);
         read_dword(&chunk_ptr, &chunk_size);
 
+        if (!require_space(chunk_ptr - data, chunk_size, data_size))
+        {
+            WARN("Invalid chunk size %#x (data size %#lx, chunk offset %#x).\n", chunk_size, data_size, chunk_offset);
+            return E_FAIL;
+        }
+
         hr = chunk_handler(chunk_ptr, chunk_size, chunk_tag, ctx);
         if (FAILED(hr)) break;
     }
-- 
2.1.4