[tarantool-patches] [PATCH 1/1] iproto: protect from false-correct size in msg header
Konstantin Osipov
kostja at tarantool.org
Mon Jun 25 16:55:37 MSK 2018
* Vladislav Shpilevoy <v.shpilevoy at tarantool.org> [18/06/18 22:55]:
Please move the check for buffer overflow to
iproto_enqueue_batch(). We should not pass invalid packet lengths
to iproto_connection_input_buffer().
> Consider this packet:
>
> msgpack = require('msgpack')
> data = msgpack.encode(18400000000000000000)..'aaaaaaa'
>
> Tarantool interprets 18400000000000000000 as size of a coming
> iproto request, and tries with no any checks to allocate buffer
> of such size. It calculates needed capacity like this:
>
> capacity = start_value;
> while (capacity < size)
> capacity *= 2;
>
> Here it is possible that on i-th iteration 'capacity' < 'size',
> but 'capacity * 2' overflows 64 bits and becomes < 'size' again,
> so this loop never ends and occupies 100% CPU.
>
> Strictly speaking overflow has undefined behavior. On the
> original system it led to nullifying 'capacity'.
>
> Such size is improbable as a real packet gabarits, but can appear
> as a result of parsing of some invalid packet, first bytes of
> which accidentally appears to be valid MessagePack uint. This is
> how the bug emerged on the real system.
>
> Lets restrict the maximal packet size to 2GB.
>
> Closes #3464
> ---
> Branch: https://github.com/tarantool/tarantool/tree/gerold103/gh-3464-iproto-100-cpu
> Issue: https://github.com/tarantool/tarantool/issues/3464
>
> src/box/iproto.cc | 15 +++++++++++++--
> test/box/net.box.result | 22 ++++++++++++++++++++++
> test/box/net.box.test.lua | 10 ++++++++++
> 3 files changed, 45 insertions(+), 2 deletions(-)
--
Konstantin Osipov, Moscow, Russia, +7 903 626 22 32
http://tarantool.io - www.twitter.com/kostja_osipov
More information about the Tarantool-patches
mailing list