[C API] Add null check in BinaryenTableGrow for missing table#8376
Open
sumleo wants to merge 1 commit intoWebAssembly:mainfrom
Open
[C API] Add null check in BinaryenTableGrow for missing table#8376sumleo wants to merge 1 commit intoWebAssembly:mainfrom
sumleo wants to merge 1 commit intoWebAssembly:mainfrom
Conversation
BinaryenTableGrow has a convenience path where passing value=nullptr auto-creates a ref.null of the table's element type. However, it calls getTableOrNull(name) and immediately dereferences the result without checking for null. If the table name doesn't exist in the module, this causes a null pointer dereference. Add a null check after getTableOrNull so that if the table doesn't exist, value remains nullptr and downstream code handles the error.
kripken
reviewed
Feb 25, 2026
| auto* table = (*(Module*)module).getTableOrNull(name); | ||
| if (table) { | ||
| value = BinaryenRefNull(module, (BinaryenType)table->type.getID()); | ||
| } |
Member
There was a problem hiding this comment.
if value is null and table is not present, this will just be wrong, so I think it is better to error here, using Fatal() as done elsewhere in the file.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Summary
BinaryenTableGrowwhen the table name doesn't exist in the modulevalue == nullptrcallsgetTableOrNull(name)and immediately dereferences the result without a null checkvalueremains nullptr and downstream code handles the error gracefullyTest plan
binaryen-c.cppc-api-kitchen-sinktest continues to work (it passes a non-null value so doesn't exercise this path)