[WasmFS] mmap: avoid setting *allocated too early (#17317)

kleisauke · web-flow · commit 77da62969eb0 · 2022-07-19T12:33:13.000-07:00
Setting `*allocated` here is too early, as read errors
may occur (causing the pointer to be `free()`'d).
diff --git a/system/lib/wasmfs/syscalls.cpp b/system/lib/wasmfs/syscalls.cpp
@@ -1529,7 +1529,6 @@ intptr_t _mmap_js(
   if (!ptr) {
     return -ENOMEM;
   }
-  *allocated = true;
 
   auto written = file->locked().read(ptr, length, offset);
   if (written < 0) {

Original file line number	Diff line number	Diff line change
`@@ -1529,7 +1529,6 @@ intptr_t _mmap_js(`
`1529`	`1529`	`if (!ptr) {`
`1530`	`1530`	`return -ENOMEM;`
`1531`	`1531`	`}`
`1532`		`- *allocated = true;`
`1533`	`1532`
`1534`	`1533`	`auto written = file->locked().read(ptr, length, offset);`
`1535`	`1534`	`if (written < 0) {`