Wasmtime GitHub notifications bot (Sep 06 2023 at 15:08): Wasmtime GitHub notifications bot (Sep 06 2023 at 15:08):alexcrichton opened PR #6968 from alexcrichton:fix-stack-overflow to bytecodealliance:main:
This commit removes recursion from AMode lowering rules for both the x64 and aarch64 backends. On the x64 backend this can lead to stack overflow on the host given wasm inputs during compilation due to the fact that
i32.addgoes through this path of lowering (e.g. trying to use theleainstruction). The recursion in these rules are rewritten to hunt for constants differently in a non-recursive fashion which relies on egraph optimizations to place constants in the right place to get good code output.This PR additionally updates the AArch64 backend to remove the recursion there as well. While not reachable from wasm this is still reachable from Cranelift and is a good bug to fix regardless.
Note that the stack overflow during compilation requires optimizations to be disabled, as otherwise egraphs will already fold constants together which means that recursion won't happen deeply.
Thanks to DFINITY for notifying the security@bytecodealliance.org mailing list for this issue! We concluded this in the end wasn't a CVE-worthy issue because it requires non-default settings to trigger (e.g. disabling optimizations). This is something I'll backport to the 13 release branch, however.
Wasmtime GitHub notifications bot (Sep 06 2023 at 15:09):alexcrichton requested wasmtime-compiler-reviewers for a review on PR #6968.
Wasmtime GitHub notifications bot (Sep 06 2023 at 15:09):alexcrichton requested fitzgen for a review on PR #6968.
Wasmtime GitHub notifications bot (Sep 06 2023 at 15:09):alexcrichton requested wasmtime-core-reviewers for a review on PR #6968.
Wasmtime GitHub notifications bot (Sep 11 2023 at 15:51):cfallin submitted PR review:
Carrying over LGTM from private branch -- thanks!
Wasmtime GitHub notifications bot (Sep 11 2023 at 16:40):alexcrichton merged PR #6968.
Last updated: Dec 23 2024 at 12:05 UTC