Double-fetch of root_size in fastrpc_pack_root_sharedpage leads to buffer overflow [399463073] - Project Zero

https://project-zero.issues.chromium.org/issues/399463073

https://twitter.com/home/status/1938227105533464638

https://twitter.com/home/status/1938294107580874949

https://twitter.com/home/status/1938313111758372947