fix(bytecode): reject high-bit-set atom indices in JS_ReadObjectAtoms#1485
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andreasrosdal wants to merge 1 commit into
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fix(bytecode): reject high-bit-set atom indices in JS_ReadObjectAtoms#1485andreasrosdal wants to merge 1 commit into
andreasrosdal wants to merge 1 commit into
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The constant-atom validation used __JS_AtomIsConst(atom), defined as ((int32_t)atom < JS_ATOM_END). Atom values with the high bit set became negative as int32_t and compared "less than JS_ATOM_END", slipping past the check and ending up in s->idx_to_atom for later use as property keys / lookup tags. Use an unsigned comparison: 0 (JS_ATOM_NULL) and >= JS_ATOM_END are both rejected. Test: api-test now hands JS_ReadObject a hand-crafted bytecode blob whose type-0 atom slot holds 0x80000001. Before the fix the reader accepts the blob and returns a non-exception value; after the fix the reader throws "out of range atom".
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The constant-atom validation used __JS_AtomIsConst(atom), defined as ((int32_t)atom < JS_ATOM_END). Atom values with the high bit set became negative as int32_t and compared "less than JS_ATOM_END", slipping past the check and ending up in s->idx_to_atom for later use as property keys / lookup tags.
Use an unsigned comparison: 0 (JS_ATOM_NULL) and >= JS_ATOM_END are both rejected.
Test: api-test now hands JS_ReadObject a hand-crafted bytecode blob whose type-0 atom slot holds 0x80000001. Before the fix the reader accepts the blob and returns a non-exception value; after the fix the reader throws "out of range atom".