Harden shared library with full RELRO and immediate binding - #320
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Add -Wl,-z,relro,-z,now (Linux-only guard) so the GOT is read-only after load and all symbols bind at load time. Verified via readelf: GNU_RELRO segment + BIND_NOW present in pg_tle.so.
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What
Add
-Wl,-z,relro,-z,nowtoPG_LDFLAGSso the builtpg_tle.sogets full RELRO (GOT read-only after load) and immediate binding (all symbols resolved at load time). This makes the GOT a non-writable target, mitigating GOT-overwrite exploitation techniques.Guarded to Linux, since
-z ...is a GNU-ld/lld option that Apple'sldrejects:Verification
Built against PG 17 and confirmed the flags land in the
.so:Runtime behavior is unchanged; this is link-time hardening only.
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