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Fix potential use-after-free in emitFuncToBlock exposed by enabling o… #23218

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Merged
merged 1 commit into from
Mar 11, 2019
Merged

Fix potential use-after-free in emitFuncToBlock exposed by enabling o… #23218

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7 changes: 5 additions & 2 deletions lib/SILGen/SILGenBridging.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -514,7 +514,7 @@ ManagedValue SILGenFunction::emitFuncToBlock(SILLocation loc,
// the block is ultimately destroyed checking that the closure is uniquely
// referenced.
bool useWithoutEscapingVerification = false;
ManagedValue escaping;
ManagedValue escaping;
if (loweredFuncTy->isNoEscape()) {
auto escapingTy = loweredFuncTy->getWithExtInfo(
loweredFuncTy->getExtInfo().withNoEscape(false));
Expand All @@ -525,8 +525,11 @@ ManagedValue SILGenFunction::emitFuncToBlock(SILLocation loc,
auto escapingAnyTy =
funcType.withExtInfo(funcType->getExtInfo().withNoEscape(false));
funcType = escapingAnyTy;
fn = B.createCopyValue(loc, escaping);
fn = escaping.copy(*this, loc);
useWithoutEscapingVerification = true;
} else {
// Since we are going to be storing this into memory, we need fn at +1.
fn = fn.ensurePlusOne(*this, loc);
}

// Build the invoke function signature. The block will capture the original
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4 changes: 2 additions & 2 deletions test/PrintAsObjC/blocks.swift
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@@ -1,8 +1,8 @@
// Please keep this file in alphabetical order!

// RUN: %empty-directory(%t)
// RUN: %target-swift-frontend(mock-sdk: %clang-importer-sdk) -emit-module -o %t %s -disable-objc-attr-requires-foundation-module
// RUN: %target-swift-frontend(mock-sdk: %clang-importer-sdk) -parse-as-library %t/blocks.swiftmodule -typecheck -emit-objc-header-path %t/blocks.h -import-objc-header %S/../Inputs/empty.h -disable-objc-attr-requires-foundation-module
// RUN: %target-swift-frontend(mock-sdk: %clang-importer-sdk) -enable-sil-ownership -emit-module -o %t %s -disable-objc-attr-requires-foundation-module
// RUN: %target-swift-frontend(mock-sdk: %clang-importer-sdk) -enable-sil-ownership -parse-as-library %t/blocks.swiftmodule -typecheck -emit-objc-header-path %t/blocks.h -import-objc-header %S/../Inputs/empty.h -disable-objc-attr-requires-foundation-module
// RUN: %FileCheck %s < %t/blocks.h
// RUN: %check-in-clang %t/blocks.h

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9 changes: 8 additions & 1 deletion test/SILGen/objc_block_to_func_to_block.swift
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@@ -1,8 +1,15 @@
// RUN: %target-swift-frontend(mock-sdk: %clang-importer-sdk) -import-objc-header %S/Inputs/objc_block_to_func_to_block.h -emit-silgen -verify %s
// RUN: %target-swift-frontend(mock-sdk: %clang-importer-sdk) -enable-sil-ownership -import-objc-header %S/Inputs/objc_block_to_func_to_block.h -emit-silgen -verify %s
// REQUIRES: objc_interop

import Foundation

func bar<A>(x: Foo<A>) {
x.blockInception { f in f { _ = $0 } }
}

typealias MyBlockWithEscapingParam = (@escaping () -> ()) -> Int

// Make sure that we properly create thunks for objc_block_to_func_to_block
@objc class ObjCClass : NSObject {
@objc func blockWithBlockTypealias(_ block: MyBlockWithEscapingParam) {}
}