[wasm][jspi] Reintroduce an SBXCHECK

thibaudmichaud · V8 LUCI CQ · commit 25e22b601c7d · 2025-06-05T04:34:45.000-07:00
Reintroduce an SBXCHECK to ensure that we always suspend/return to the immediate parent stack. Returning should already be safe because the StackMemory chain lives outside of the sandbox, but suspending is still unsafe because it uses the in-sandbox WasmSuspenderObject chain which can be corrupted. This is a short-term fix. A more robust solution will be to move the WasmSuspenderObjects outside of the sandbox, like we did with the WasmContinuationObjects (https://crrev.com/c/6426203). R=jkummerow@chromium.org Fixed: chromium:422645418 Change-Id: I08a60303ff65a07ae0ae4bd2f1e8758b174fba1a Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/6623289 Reviewed-by: Jakob Kummerow <jkummerow@chromium.org> Commit-Queue: Thibaud Michaud <thibaudm@chromium.org> Cr-Commit-Position: refs/heads/main@{#100689}
diff --git a/src/execution/isolate.cc b/src/execution/isolate.cc
@@ -3942,7 +3942,7 @@ void Isolate::SwitchStacks(wasm::StackMemory* from, wasm::StackMemory* to) {
     // TODO(388533754): This check won't hold anymore with core stack-switching.
     // Instead, we will need to validate all the intermediate stacks and also
     // check that they don't hold central stack frames.
-    DCHECK_EQ(from->jmpbuf()->parent, to);
+    SBXCHECK_EQ(from->jmpbuf()->parent, to);
   }
   uintptr_t limit = reinterpret_cast<uintptr_t>(to->jmpbuf()->stack_limit);
   stack_guard()->SetStackLimitForStackSwitching(limit);

Original file line number	Diff line number	Diff line change
`@@ -3942,7 +3942,7 @@ void Isolate::SwitchStacks(wasm::StackMemory* from, wasm::StackMemory* to) {`
`3942`	`3942`	`// TODO(388533754): This check won't hold anymore with core stack-switching.`
`3943`	`3943`	`// Instead, we will need to validate all the intermediate stacks and also`
`3944`	`3944`	`// check that they don't hold central stack frames.`
`3945`		`- DCHECK_EQ(from->jmpbuf()->parent, to);`
	`3945`	`+ SBXCHECK_EQ(from->jmpbuf()->parent, to);`
`3946`	`3946`	`}`
`3947`	`3947`	`uintptr_t limit = reinterpret_cast<uintptr_t>(to->jmpbuf()->stack_limit);`
`3948`	`3948`	`stack_guard()->SetStackLimitForStackSwitching(limit);`