mrminer reports: Lua prerequirements for NPCs: ... #6015

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yourland-report · 2024-01-19T20:47:11Z

yourland-report commented

2024-01-19 20:47:11 +00:00

mrminer reports a bug:

Lua prerequirements for NPCs: e.g. 'return (npc.properties["foo"] * 2) != npc.properties["bar"]'

Player position:

{
	x = 3045.4150390625,
	y = 123.56199645996,
	z = 308.92901611328
}

Player look:

{
	x = 0.89370530843735,
	y = -0.33693096041679,
	z = -0.29625716805458
}

Player information:

{
	avg_jitter = 0.0020000040531158,
	connection_uptime = 470,
	serialization_version = 29,
	patch = 0,
	minor = 7,
	lang_code = "",
	state = "Active",
	protocol_version = 42,
	major = 5,
	formspec_version = 6,
	min_jitter = 0,
	version_string = "5.7.0",
	ip_version = 6,
	min_rtt = 0.11299999803305,
	avg_rtt = 0.11999999731779,
	max_rtt = 1.5930000543594,
	max_jitter = 1.4620000123978
}

Player meta:

{
	fields = {
		["stamina:exhaustion"] = "105.5",
		yl_commons_thankyou = "81",
		jointime = "1646186882",
		bitten = "0",
		["ocean_build.last_warning"] = "1.6733e+09",
		["ocean_build.forbidden"] = "true",
		["ocean_build.ocean_built"] = "12",
		punch_count = "27715",
		hud_state = "on",
		inflicted_damage = "570270",
		["petz:werewolf"] = "0",
		["petz:lycanthropy"] = "0",
		["petz:werewolf_vignette_id"] = "19",
		yl_church = "return {[\"last_death_portal\"] = 1705618734, [\"last_heal\"] = 1677356984, [\"last_death\"] = {[\"x\"] = 3012, [\"y\"] = 109, [\"z\"] = 228}}",
		placed_nodes = "79953",
		partychat = "party",
		played_time = "4386164",
		arenalib_watchID = "0",
		yl_commons_player_joined = "1705696779",
		died = "720",
		crafted = "61656",
		["unified_inventory:bags"] = "return {\"unified_inventory:bag_large\", \"unified_inventory:bag_large\", \"unified_inventory:bag_large\", \"unified_inventory:bag_large\"}",
		["petz:old_override_table"] = "return {[\"new_move\"] = true, [\"jump\"] = 1.5, [\"gravity\"] = 1, [\"sneak_glitch\"] = false, [\"speed\"] = 2, [\"sneak\"] = true}",
		arenalib_infobox_arenaID = "0",
		xp = "75533",
		["signslib:pos"] = "(2934,92,339)",
		["3d_armor_inventory"] = "return {\"shields:shield_crystal 1 48755\", \"3d_armor:helmet_nether 1 48755\", \"3d_armor:boots_crystal 1 48730\", \"3d_armor:leggings_crystal 1 48755\", \"3d_armor:chestplate_crystal 1 3580\", \"\"}",
		yl_commons_player_created = "1646186882",
		["petz:werewolf_clan_idx"] = "4",
		digged_nodes = "187161",
		["hud_manager:choppy:waypoint_enabled"] = "y",
		["stamina:level"] = "6",
		repellant = "0",
		["stamina:poisoned"] = "no"
	}
}

Log identifier


[MOD] yl_report log identifier = 5TYKNhaXvtHBjgcgy5JIsWOQLFBuoytv

Profiler save:

profile-20240119T204711.json_prettyEE

Status:

# Server: version: 5.7.0-yl-thx-tmm | game: Minetest Game | uptime: 2d 4h 33min 26s | max lag: 1.2s | clients (25/52): 473, AliasAlreadyTaken, Bailiff, BLuOXide, Boot, BTS-, Calamity_Jones, daydream, flux, jackofthebean000, Keya, Lupercus, Makk5im, mrminer, Murmel, Pelu, poppyasdan, rewired_X, rheo, Service, Sokomine, STEALTH, tagtraum, thatchristianguy, Tute

Teleport command:

/teleport xyz 3045 124 309

Compass command:

/give_compass Construction 5TYKNhaXvtHBjgcgy5JIsWOQLFBuoytv D2691E 3045 124 309

mrminer reports a bug: > Lua prerequirements for NPCs: e.g. 'return (npc.properties["foo"] * 2) != npc.properties["bar"]' Player position: ``` { x = 3045.4150390625, y = 123.56199645996, z = 308.92901611328 } ``` Player look: ``` { x = 0.89370530843735, y = -0.33693096041679, z = -0.29625716805458 } ``` Player information: ``` { avg_jitter = 0.0020000040531158, connection_uptime = 470, serialization_version = 29, patch = 0, minor = 7, lang_code = "", state = "Active", protocol_version = 42, major = 5, formspec_version = 6, min_jitter = 0, version_string = "5.7.0", ip_version = 6, min_rtt = 0.11299999803305, avg_rtt = 0.11999999731779, max_rtt = 1.5930000543594, max_jitter = 1.4620000123978 } ``` Player meta: ``` { fields = { ["stamina:exhaustion"] = "105.5", yl_commons_thankyou = "81", jointime = "1646186882", bitten = "0", ["ocean_build.last_warning"] = "1.6733e+09", ["ocean_build.forbidden"] = "true", ["ocean_build.ocean_built"] = "12", punch_count = "27715", hud_state = "on", inflicted_damage = "570270", ["petz:werewolf"] = "0", ["petz:lycanthropy"] = "0", ["petz:werewolf_vignette_id"] = "19", yl_church = "return {[\"last_death_portal\"] = 1705618734, [\"last_heal\"] = 1677356984, [\"last_death\"] = {[\"x\"] = 3012, [\"y\"] = 109, [\"z\"] = 228}}", placed_nodes = "79953", partychat = "party", played_time = "4386164", arenalib_watchID = "0", yl_commons_player_joined = "1705696779", died = "720", crafted = "61656", ["unified_inventory:bags"] = "return {\"unified_inventory:bag_large\", \"unified_inventory:bag_large\", \"unified_inventory:bag_large\", \"unified_inventory:bag_large\"}", ["petz:old_override_table"] = "return {[\"new_move\"] = true, [\"jump\"] = 1.5, [\"gravity\"] = 1, [\"sneak_glitch\"] = false, [\"speed\"] = 2, [\"sneak\"] = true}", arenalib_infobox_arenaID = "0", xp = "75533", ["signslib:pos"] = "(2934,92,339)", ["3d_armor_inventory"] = "return {\"shields:shield_crystal 1 48755\", \"3d_armor:helmet_nether 1 48755\", \"3d_armor:boots_crystal 1 48730\", \"3d_armor:leggings_crystal 1 48755\", \"3d_armor:chestplate_crystal 1 3580\", \"\"}", yl_commons_player_created = "1646186882", ["petz:werewolf_clan_idx"] = "4", digged_nodes = "187161", ["hud_manager:choppy:waypoint_enabled"] = "y", ["stamina:level"] = "6", repellant = "0", ["stamina:poisoned"] = "no" } } ``` Log identifier ``` [MOD] yl_report log identifier = 5TYKNhaXvtHBjgcgy5JIsWOQLFBuoytv ``` Profiler save: ``` profile-20240119T204711.json_prettyEE ``` Status: ``` # Server: version: 5.7.0-yl-thx-tmm | game: Minetest Game | uptime: 2d 4h 33min 26s | max lag: 1.2s | clients (25/52): 473, AliasAlreadyTaken, Bailiff, BLuOXide, Boot, BTS-, Calamity_Jones, daydream, flux, jackofthebean000, Keya, Lupercus, Makk5im, mrminer, Murmel, Pelu, poppyasdan, rewired_X, rheo, Service, Sokomine, STEALTH, tagtraum, thatchristianguy, Tute ``` Teleport command: ``` /teleport xyz 3045 124 309 ``` Compass command: ``` /give_compass Construction 5TYKNhaXvtHBjgcgy5JIsWOQLFBuoytv D2691E 3045 124 309 ```

AliasAlreadyTaken was assigned by yourland-report

2024-01-19 20:47:11 +00:00

AliasAlreadyTaken commented

2024-01-19 23:06:04 +00:00

Could be used to execute any code, right?

whosit commented

2024-01-20 02:22:53 +00:00

Any code in the same way as luac can execute any code. So it's doable.

AliasAlreadyTaken added the

1. kind/enhancement

label 2024-01-20 02:38:59 +00:00

flux commented

2024-01-21 04:48:20 +00:00

Could be used to execute any code, right?
Any code in the same way as luac can execute any code. So it's doable.

luacs only have access to a very limited subset of the lua public libraries that minetest has built in. also, they are coded to limit the execution time of individual luacs - but i'm not too sure how they do that. but i know they do it, or it'd be trivial to DOS a server (while true do a = 1 end).

luacs can execute arbitrary code that's written in that specific luac, but they don't have access to all the lua libraries, and their input is also limited.

> Could be used to execute any code, right? > Any code in the same way as luac can execute any code. So it's doable. luacs only have access to a very limited subset of the lua public libraries that minetest has built in. also, they are coded to limit the execution time of individual luacs - but i'm not too sure how they do that. but i know they do it, or it'd be trivial to DOS a server (`while true do a = 1 end`). luacs can execute arbitrary code that's written in that specific luac, but they don't have access to all the lua libraries, and their input is also limited.

whosit commented

2024-01-21 05:29:38 +00:00

Luacs limit execution time by using a debug hook that gets called after a number of "events" (basically lua bytecode instructions):
debug.sethook(timeout, "", MAXEVENTS) (you also need to disable jit compilation for this to work).
It's not perfect for limiting execution time (because it's possible to use expensive bytecode instructions in a loop, and this counts the number of them, not actual execution time).

And yes, lua allows to fully control the environment in which the code gets executed - you can throw away or override any functions you don't need or add some npc-specific functions.

Luacs limit execution time by using a debug hook that gets called after a number of "events" (basically lua bytecode instructions): `debug.sethook(timeout, "", MAXEVENTS)` (you also need to disable jit compilation for this to work). It's not perfect for limiting execution time (because it's possible to use expensive bytecode instructions in a loop, and this counts the number of them, not actual execution time). And yes, lua allows to fully control the environment in which the code gets executed - you can throw away or override any functions you don't need or add some npc-specific functions.

flux commented

2024-01-23 02:22:36 +00:00

It's not perfect for limiting execution time (because it's possible to use expensive bytecode instructions in a loop, and this counts the number of them, not actual execution time).

another good example is that string.match can have near-exponential run-time with certain carefully crafted patterns, (presumably only using 1 lua "event"), so that's not available on the luac.

> It's not perfect for limiting execution time (because it's possible to use expensive bytecode instructions in a loop, and this counts the number of them, not actual execution time). another good example is that string.match can have near-exponential run-time with certain carefully crafted patterns, (presumably only using 1 lua "event"), so that's not available on the luac.

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