nx_savedata: Ensure heap safety

bdk/libs/nx_savedata/remap_storage.c

@@ -102,7 +102,7 @@ uint32_t save_remap_storage_read(remap_storage_ctx_t *ctx, void *buffer, uint64_
     }
     uint64_t in_pos = offset;
     uint32_t out_pos = 0;
-    uint32_t remaining = count;
+    uint32_t remaining = (u32)count;
 
     while (remaining) {
         uint64_t entry_pos = in_pos - entry->entry.virtual_offset;
@@ -135,7 +135,7 @@ uint32_t save_remap_storage_write(remap_storage_ctx_t *ctx, const void *buffer,
     }
     uint64_t in_pos = offset;
     uint32_t out_pos = 0;
-    uint32_t remaining = count;
+    uint32_t remaining = (u32)count;
 
     while (remaining) {
         uint64_t entry_pos = in_pos - entry->entry.virtual_offset;

bdk/libs/nx_savedata/save.c

@@ -143,6 +143,11 @@ bool save_process(save_ctx_t *ctx) {
         }
     }
 
+    if (ctx->header.layout.version > VERSION_DISF_5) {
+        EPRINTF("Unsupported save version.\nLibrary must be updated.");
+        return false;
+    }
+
     /* Initialize remap storages. */
     ctx->data_remap_storage.header = &ctx->header.main_remap_header;
     ctx->meta_remap_storage.header = &ctx->header.meta_remap_header;
@@ -232,36 +237,64 @@ bool save_process(save_ctx_t *ctx) {
 }
 
 void save_free_contexts(save_ctx_t *ctx) {
+    if (ctx->data_remap_storage.header) {
         for (unsigned int i = 0; i < ctx->data_remap_storage.header->map_segment_count; i++) {
+            if (ctx->data_remap_storage.segments && ctx->data_remap_storage.segments[i].entries)
                 free(ctx->data_remap_storage.segments[i].entries);
         }
+    }
+    if (ctx->data_remap_storage.segments)
         free(ctx->data_remap_storage.segments);
+
+    if (ctx->meta_remap_storage.header) {
         for (unsigned int i = 0; i < ctx->meta_remap_storage.header->map_segment_count; i++) {
+            if (ctx->meta_remap_storage.segments && ctx->meta_remap_storage.segments[i].entries)
                 free(ctx->meta_remap_storage.segments[i].entries);
         }
+    }
+    if (ctx->meta_remap_storage.segments)
         free(ctx->meta_remap_storage.segments);
+
+    if (ctx->data_remap_storage.map_entries)
         free(ctx->data_remap_storage.map_entries);
+    if (ctx->meta_remap_storage.map_entries)
         free(ctx->meta_remap_storage.map_entries);
+
     for (unsigned int i = 0; i < 2; i++) {
+        if (ctx->duplex_storage.layers[i].bitmap.bitmap)
             free(ctx->duplex_storage.layers[i].bitmap.bitmap);
+        if (ctx->duplex_storage.layers[i].data_a.base_storage.ctx)
             free(ctx->duplex_storage.layers[i].data_a.base_storage.ctx);
+        if (ctx->duplex_storage.layers[i].data_b.base_storage.ctx)
             free(ctx->duplex_storage.layers[i].data_b.base_storage.ctx);
     }
+    if (ctx->duplex_storage.layers[1].bitmap_storage.base_storage.ctx)
         free(ctx->duplex_storage.layers[1].bitmap_storage.base_storage.ctx);
+
+    if (ctx->journal_storage.map.map_storage)
         free(ctx->journal_storage.map.map_storage);
+    if (ctx->journal_storage.map.entries)
         free(ctx->journal_storage.map.entries);
+
     for (unsigned int i = 0; i < 4; i++) {
+        if (ctx->core_data_ivfc_storage.integrity_storages[i].block_validities)
             free(ctx->core_data_ivfc_storage.integrity_storages[i].block_validities);
         save_cached_storage_finalize(&ctx->core_data_ivfc_storage.levels[i + 1]);
     }
+    if (ctx->core_data_ivfc_storage.level_validities)
         free(ctx->core_data_ivfc_storage.level_validities);
+
     if (ctx->header.layout.version >= VERSION_DISF_5) {
         for (unsigned int i = 0; i < 3; i++) {
+            if (ctx->fat_ivfc_storage.integrity_storages[i].block_validities)
                 free(ctx->fat_ivfc_storage.integrity_storages[i].block_validities);
             save_cached_storage_finalize(&ctx->fat_ivfc_storage.levels[i + 1]);
         }
     }
+    if (ctx->fat_ivfc_storage.level_validities)
         free(ctx->fat_ivfc_storage.level_validities);
+
+    if (ctx->fat_storage)
         free(ctx->fat_storage);
 }
 

bdk/libs/nx_savedata/storage.c

@@ -45,11 +45,6 @@ OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 
 #include <string.h>
 
-void storage_init(storage *this, const storage_vt *vt, void *ctx) {
-    this->vt = vt;
-    this->ctx = ctx;
-}
-
 void substorage_init(substorage *this, const storage_vt *vt, void *ctx, uint64_t offset, uint64_t length) {
     storage_init(&this->base_storage, vt, ctx);
     this->offset = offset;

bdk/libs/nx_savedata/storage.h

@@ -51,7 +51,10 @@ typedef struct {
     void *ctx;
 } storage;
 
-void storage_init(storage *this, const storage_vt *vt, void *ctx);
+static void ALWAYS_INLINE storage_init(storage *this, const storage_vt *vt, void *ctx) {
+    this->vt = vt;
+    this->ctx = ctx;
+}
 
 typedef struct {
     uint64_t offset;