Disable loading of Lua bytecode#3
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Loading untrusted Lua bytecode is unsafe — the LuaJIT FAQ explicitly states the bytecode loader does not validate input, and maliciously crafted bytecode can crash the VM or be used for sandbox escapes (type confusion, OOB reads, fake GCobj pointers). Reject any chunk whose lexer setup detects bytecode (BCDUMP_HEAD1, i.e. 0x1B at the start of the stream). All chunk-loading APIs — lua_load, lua_loadx, luaL_loadbuffer(x), luaL_loadfile(x) — funnel through cpparser, so this single check covers loadstring, load, string.dump round-trips, and any host-side luaL_loadbuffer call. Source loading is unaffected. This mirrors the approach Redis took for vanilla Lua in redis/redis@fdf9d455.
PragmaTwice
approved these changes
May 17, 2026
jihuayu
approved these changes
May 17, 2026
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Loading untrusted Lua bytecode is unsafe — the LuaJIT FAQ explicitly states the bytecode loader does not validate input, and maliciously crafted bytecode can crash the VM or be used for sandbox escapes (type confusion, OOB reads, fake GCobj pointers).
Reject any chunk whose lexer setup detects bytecode (BCDUMP_HEAD1, i.e. 0x1B at the start of the stream). All chunk-loading APIs — lua_load, lua_loadx, luaL_loadbuffer(x), luaL_loadfile(x) — funnel through cpparser, so this single check covers loadstring, load, string.dump round-trips, and any host-side luaL_loadbuffer call.
Source loading is unaffected. This mirrors the approach Redis took for vanilla Lua in redis/redis@fdf9d455.