[Tarantool-patches] [PATCH luajit] Make string to number conversions fail on NUL char

[Igor Munkin]

Kirill,

We discussed offline with Sasha and his review looks to be excess
considering Sergos' ack and the patch presence in upstream.

Please proceed.

On 14.02.20, Igor Munkin wrote:
> The routine used for conversion a string representation to number
> (lj_strscan_scan) doesn't respect the size of the given string/buffer.
> Such behaviour leads to the following results:
> 
> | local a = tonumber("inf\x00imun")   -- the result is 'inf'
> | local b = tonumber("\x36\x00\x80") -- the result is 6
> 
> The behaviour described above is similar to the one vanila Lua 5.1 has:
> 
> | $ ./lua -e 'print(_VERSION, tonumber("inf"..string.char(0).."imun"))'
> | Lua 5.1	inf
> 
> However, the issue is fixed in Lua 5.2 and the results are the following:
> | $ ./lua -e 'print(_VERSION, tonumber("inf"..string.char(0).."imun"))'
> | Lua 5.2	nil
> 
> The patch introduces additional parameter to lj_strscan_scan routine to
> detect whether there is nothing left after the null character.
> 
> Relates to tarantool#4773
> 
> Reported-by: Alexander Turenko <alexander.turenko at tarantool.org>

Added Sergos' ack, force-pushed to the branch.

> Signed-off-by: Igor Munkin <imun at tarantool.org>
> ---
> 
> This is a backport of the origin commit from v2.1 branch in LuaJIT
> repo extended with tests and commit message. Commit subject is left
> unchanged with the respect to the origin commit.
> 
> Upstream commit: https://github.com/LuaJIT/LuaJIT/commit/0ad60ccbc3768fa8e3e726858adf261950edbc22
> Issue: https://github.com/tarantool/tarantool/issues/4773
> Branch: https://github.com/tarantool/luajit/tree/imun/tonumber-fail-on-NUL-char
> 
>  src/lj_cparse.c                               |  3 ++-
>  src/lj_lex.c                                  |  2 +-
>  src/lj_strscan.c                              | 11 +++++----
>  src/lj_strscan.h                              |  3 ++-
>  ...gh-4773-tonumber-fail-on-NUL-char.test.lua | 24 +++++++++++++++++++
>  5 files changed, 36 insertions(+), 7 deletions(-)
>  create mode 100755 test/gh-4773-tonumber-fail-on-NUL-char.test.lua
> 

<snipped>

> -- 
> 2.25.0
> 

-- 
Best regards,
IM