Re: [Tarantool-patches] [PATCH v1 1/1] box: remove unnecessary rights from peristent functions

[Sergey Ostanevich <s.ostanevich@corp.mail.ru>]

Hi!

Thanks for the patch!

I wonder why we should have this strange naming for the function of
backport 2_7_1 from 2_7_1 itself. Perhaps just the ‘function_access’
is enough?

Otherwise LGTM.

Sergos


> On 21 Dec 2020, at 13:51, Mergen Imeev via Tarantool-patches <tarantool-patches@dev.tarantool.org> wrote:
> 
> After this patch, the persistent functions "box.schema.user.info" and
> "LUA" will have the same rights as the user who executed them.
> 
> The problem was that setuid was unnecessarily set. Because of this,
> these functions had the same rights as the user who created them.
> However, they must have the same rights as the user who used them.
> 
> Fixes tarantool/security#1
> ---
> https://github.com/tarantool/security/issues/1
> https://github.com/tarantool/tarantool/tree/imeevma/gh-security-1-lua-function-access
> 
> @ChangeLog
> - The functions "LUA" and "box.schema.user.info" now have the
>   same rights as the user who executes them. (gh-security-1).
> 
> 
> src/box/bootstrap.snap       | Bin 5976 -> 5991 bytes
> src/box/lua/upgrade.lua      |  30 +++++++++++++++++++++++++++++
> test/box-py/bootstrap.result |   4 ++--
> test/box/access.result       |  36 +++++++++++++++++++++++++++++++++++
> test/box/access.test.lua     |  15 +++++++++++++++
> 5 files changed, 83 insertions(+), 2 deletions(-)
> 
> diff --git a/src/box/bootstrap.snap b/src/box/bootstrap.snap
> index 8bd4f7ce24216a8bcced6aa97c20c83eb7a02c77..9e7a4e3291accfc387b315f85be9b01f443048fd 100644
> 
> diff --git a/src/box/lua/upgrade.lua b/src/box/lua/upgrade.lua
> index a86a0d410..09cd015f0 100644
> --- a/src/box/lua/upgrade.lua
> +++ b/src/box/lua/upgrade.lua
> @@ -971,6 +971,35 @@ local function upgrade_to_2_3_1()
>     create_session_settings_space()
> end
> 
> +--------------------------------------------------------------------------------
> +-- Tarantool 2.7.1
> +--------------------------------------------------------------------------------
> +local function backport_upgrade_2_7_1_function_access()
> +    local _func = box.space._func
> +    local _priv = box.space._priv
> +    local datetime = os.date("%Y-%m-%d %H:%M:%S")
> +    local funcs_to_change = {'LUA', 'box.schema.user.info'}
> +    for _, name in pairs(funcs_to_change) do
> +        local func = _func.index['name']:get(name)
> +        if func ~= nil and func.setuid ~= 0 then
> +            local id = func.id
> +            log.info('remove old function "'..name..'"')
> +            _priv:delete({2, 'function', id})
> +            _func:delete({id})
> +            log.info('create function "'..name..'" with unset setuid')
> +            local new_func = func:update({{'=', 4, 0}, {'=', 18, datetime},
> +                                          {'=', 19, datetime}})
> +            _func:replace(new_func)
> +            log.info('grant execute on function "'..name..'" to public')
> +            _priv:replace{ADMIN, PUBLIC, 'function', id, box.priv.X}
> +        end
> +    end
> +end
> +
> +local function upgrade_to_2_7_1()
> +    backport_upgrade_2_7_1_function_access()
> +end
> +
> --------------------------------------------------------------------------------
> 
> local handlers = {
> @@ -985,6 +1014,7 @@ local handlers = {
>     {version = mkversion(2, 2, 1), func = upgrade_to_2_2_1, auto = true},
>     {version = mkversion(2, 3, 0), func = upgrade_to_2_3_0, auto = true},
>     {version = mkversion(2, 3, 1), func = upgrade_to_2_3_1, auto = true},
> +    {version = mkversion(2, 7, 1), func = upgrade_to_2_7_1, auto = true},
> }
> 
> -- Schema version of the snapshot.
> diff --git a/test/box-py/bootstrap.result b/test/box-py/bootstrap.result
> index 0876e77a6..ed7accea3 100644
> --- a/test/box-py/bootstrap.result
> +++ b/test/box-py/bootstrap.result
> @@ -4,7 +4,7 @@ box.internal.bootstrap()
> box.space._schema:select{}
> ---
> - - ['max_id', 511]
> -  - ['version', 2, 3, 1]
> +  - ['version', 2, 7, 1]
> ...
> box.space._cluster:select{}
> ---
> @@ -167,7 +167,7 @@ box.space._user:select{}
> ...
> for _, v in box.space._func:pairs{} do r = {} table.insert(r, v:update({{"=", 18, ""}, {"=", 19, ""}})) return r end
> ---
> -- - [1, 1, 'box.schema.user.info', 1, 'LUA', '', 'function', [], 'any', 'none', 'none',
> +- - [1, 1, 'box.schema.user.info', 0, 'LUA', '', 'function', [], 'any', 'none', 'none',
>     false, false, true, ['LUA'], {}, '', '', '']
> ...
> box.space._priv:select{}
> diff --git a/test/box/access.result b/test/box/access.result
> index 20b1b8b35..27e636122 100644
> --- a/test/box/access.result
> +++ b/test/box/access.result
> @@ -2141,3 +2141,39 @@ box.schema.user.revoke('guest', 'read,write,execute', 'space', 'not_universe')
> sp:drop()
> ---
> ...
> +--
> +-- Make sure that the functions "LUA" and "box.schema.user.info" do not have
> +-- excess rights.
> +--
> +_ = box.schema.func.call("LUA", "return 1")
> +---
> +...
> +_ = box.schema.func.call("LUA", "return box.space._space:count()")
> +---
> +...
> +_ = box.schema.func.call("box.schema.user.info", 0)
> +---
> +...
> +_ = box.schema.func.call("box.schema.user.info", 1)
> +---
> +...
> +session.su('guest')
> +---
> +...
> +_ = box.schema.func.call("LUA", "return 1")
> +---
> +...
> +_ = box.schema.func.call("LUA", "return box.space._space:count()")
> +---
> +- error: Read access to space '_space' is denied for user 'guest'
> +...
> +_ = box.schema.func.call("box.schema.user.info", 0)
> +---
> +...
> +_ = box.schema.func.call("box.schema.user.info", 1)
> +---
> +- error: User '1' is not found
> +...
> +session.su('admin')
> +---
> +...
> diff --git a/test/box/access.test.lua b/test/box/access.test.lua
> index 3e083a383..a62f87ad8 100644
> --- a/test/box/access.test.lua
> +++ b/test/box/access.test.lua
> @@ -824,3 +824,18 @@ box.schema.user.grant('guest', 'read,write,execute', 'space', 'not_universe')
> box.schema.user.revoke('guest', 'read,write,execute', 'universe')
> box.schema.user.revoke('guest', 'read,write,execute', 'space', 'not_universe')
> sp:drop()
> +
> +--
> +-- Make sure that the functions "LUA" and "box.schema.user.info" do not have
> +-- excess rights.
> +--
> +_ = box.schema.func.call("LUA", "return 1")
> +_ = box.schema.func.call("LUA", "return box.space._space:count()")
> +_ = box.schema.func.call("box.schema.user.info", 0)
> +_ = box.schema.func.call("box.schema.user.info", 1)
> +session.su('guest')
> +_ = box.schema.func.call("LUA", "return 1")
> +_ = box.schema.func.call("LUA", "return box.space._space:count()")
> +_ = box.schema.func.call("box.schema.user.info", 0)
> +_ = box.schema.func.call("box.schema.user.info", 1)
> +session.su('admin')
> -- 
> 2.25.1
>