[Libreoffice-commits] online.git: net/WebSocketHandler.hpp

[Libreoffice Gerrit user]

 net/WebSocketHandler.hpp |    9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

New commits:
commit 4e1ed7205d22f630b112f8edce8ba09d873fcd40
Author:     Miklos Vajna <vmiklos at collabora.com>
AuthorDate: Mon May 27 09:06:38 2019 +0200
Commit:     Miklos Vajna <vmiklos at collabora.com>
CommitDate: Mon May 27 09:06:38 2019 +0200

    net: avoid UB in WebSocketHandler::readPayload()
    
    Seen when closing a Writer document.
    
    /home/vmiklos/lode/opt_private/gcc-7.3.0/lib/gcc/x86_64-pc-linux-gnu/7.3.0/../../../../include/c++/7.3.0/bits/stl_vector.h:798:9: runtime error: reference binding to null pointer of type 'char'
        #0 0x6ff633 in std::vector<char, std::allocator<char> >::operator[](unsigned long) /home/vmiklos/lode/opt_private/gcc-7.3.0/lib/gcc/x86_64-pc-linux-gnu/7.3.0/../../../../include/c++/7.3.0/bits/stl_vector.h:798:2
        #1 0x770d0c in WebSocketHandler::readPayload(unsigned char*, unsigned long, unsigned char*, std::vector<char, std::allocator<char> >&) /home/vmiklos/lode/dev/online/./net/WebSocketHandler.hpp:611:29
        #2 0x759324 in WebSocketHandler::handleTCPStream(std::shared_ptr<StreamSocket> const&) /home/vmiklos/lode/dev/online/./net/WebSocketHandler.hpp:251:13
        #3 0x6f820d in WebSocketHandler::handleIncomingMessage(SocketDisposition&) /home/vmiklos/lode/dev/online/./net/WebSocketHandler.hpp:419:20
        #4 0xb2da64 in ClientSession::handleIncomingMessage(SocketDisposition&) /home/vmiklos/lode/dev/online/wsd/ClientSession.cpp:74:14
        #5 0xa70a61 in StreamSocket::handlePoll(SocketDisposition&, std::chrono::time_point<std::chrono::_V2::steady_clock, std::chrono::duration<long, std::ratio<1l, 1000000000l> > >, int) /home/vmiklos/lode/dev/online/./net/Socket.hpp:1037:29
        #6 0x6ec83d in SocketPoll::poll(int) /home/vmiklos/lode/dev/online/./net/Socket.hpp:570:34
        #7 0x830019 in DocumentBroker::pollThread() /home/vmiklos/lode/dev/online/wsd/DocumentBroker.cpp:286:16
        #8 0x8fdb38 in DocumentBroker::DocumentBrokerPoll::pollingThread() /home/vmiklos/lode/dev/online/wsd/DocumentBroker.cpp:165:20
        #9 0xe00e75 in SocketPoll::pollingThreadEntry() /home/vmiklos/lode/dev/online/net/Socket.cpp:184:9
        #10 0xe49cfd in void std::__invoke_impl<void, void (SocketPoll::*)(), SocketPoll*>(std::__invoke_memfun_deref, void (SocketPoll::*&&)(), SocketPoll*&&) /home/vmiklos/lode/opt_private/gcc-7.3.0/lib/gcc/x86_64-pc-linux-gnu/7.3.0/../../../../include/c++/7.3.0/bits/invoke.h:73:14
        #11 0xe4980a in std::__invoke_result<void (SocketPoll::*)(), SocketPoll*>::type std::__invoke<void (SocketPoll::*)(), SocketPoll*>(void (SocketPoll::*&&)(), SocketPoll*&&) /home/vmiklos/lode/opt_private/gcc-7.3.0/lib/gcc/x86_64-pc-linux-gnu/7.3.0/../../../../include/c++/7.3.0/bits/invoke.h:95:14
        #12 0xe496bd in decltype(std::__invoke(_S_declval<0ul>(), _S_declval<1ul>())) std::thread::_Invoker<std::tuple<void (SocketPoll::*)(), SocketPoll*> >::_M_invoke<0ul, 1ul>(std::_Index_tuple<0ul, 1ul>) /home/vmiklos/lode/opt_private/gcc-7.3.0/lib/gcc/x86_64-pc-linux-gnu/7.3.0/../../../../include/c++/7.3.0/thread:234:13
        #13 0xe494c7 in std::thread::_Invoker<std::tuple<void (SocketPoll::*)(), SocketPoll*> >::operator()() /home/vmiklos/lode/opt_private/gcc-7.3.0/lib/gcc/x86_64-pc-linux-gnu/7.3.0/../../../../include/c++/7.3.0/thread:243:11
        #14 0xe4888a in std::thread::_State_impl<std::thread::_Invoker<std::tuple<void (SocketPoll::*)(), SocketPoll*> > >::_M_run() /home/vmiklos/lode/opt_private/gcc-7.3.0/lib/gcc/x86_64-pc-linux-gnu/7.3.0/../../../../include/c++/7.3.0/thread:186:13
        #15 0x7f2c5805fe2e in execute_native_thread_routine /home/vmiklos/lode/packages/gccbuild/x86_64-pc-linux-gnu/libstdc++-v3/src/c++11/../../../../../gcc-7.3.0/libstdc++-v3/src/c++11/thread.cc:83
        #16 0x7f2c57a3c558 in start_thread (/lib64/libpthread.so.0+0x7558)
        #17 0x7f2c5715082e in clone (/lib64/libc.so.6+0xf882e)
    
    SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior /home/vmiklos/lode/opt_private/gcc-7.3.0/lib/gcc/x86_64-pc-linux-gnu/7.3.0/../../../../include/c++/7.3.0/bits/stl_vector.h:798:9 in
    
    Change-Id: Ifaf6b193e9bba480587c2e184df55aa0728bb370

diff --git a/net/WebSocketHandler.hpp b/net/WebSocketHandler.hpp
index f5f767e4f..3f3f2aac0 100644
--- a/net/WebSocketHandler.hpp
+++ b/net/WebSocketHandler.hpp
@@ -608,9 +608,12 @@ protected:
         {
             size_t end = payload.size();
             payload.resize(end + dataLen);
-            char* wsData = &payload[end];
-            for (size_t i = 0; i < dataLen; ++i)
-                *wsData++ = data[i] ^ mask[i % 4];
+            if (dataLen > 0)
+            {
+                char* wsData = &payload[end];
+                for (size_t i = 0; i < dataLen; ++i)
+                    *wsData++ = data[i] ^ mask[i % 4];
+            }
         }
         else
             payload.insert(payload.end(), data, data + dataLen);