[Lldb-commits] [lldb] r373572 - Fix a use-after-free in GDBRemoteCommunicationServerLLGS

Pavel Labath via lldb-commits lldb-commits at lists.llvm.org
Thu Oct 3 00:59:27 PDT 2019


Author: labath
Date: Thu Oct  3 00:59:26 2019
New Revision: 373572

URL: http://llvm.org/viewvc/llvm-project?rev=373572&view=rev
Log:
Fix a use-after-free in GDBRemoteCommunicationServerLLGS

Although it's called "GetString", StreamString::GetString actually
returns a StringRef. Creating a json object with a StringRef does not
make a copy, which means the StringRef will be dangling as soon as the
underlying stream is destroyed. Add a .str() to force the json object to
hold a copy of the string.

This fixes nearly every test on linux.

Modified:
    lldb/trunk/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp

Modified: lldb/trunk/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp?rev=373572&r1=373571&r2=373572&view=diff
==============================================================================
--- lldb/trunk/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp (original)
+++ lldb/trunk/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp Thu Oct  3 00:59:26 2019
@@ -462,7 +462,8 @@ GetRegistersAsJSON(NativeThreadProtocol
     WriteRegisterValueInHexFixedWidth(stream, reg_ctx, *reg_info_p,
                                       &reg_value, lldb::eByteOrderBig);
 
-    register_object.try_emplace(llvm::to_string(reg_num), stream.GetString());
+    register_object.try_emplace(llvm::to_string(reg_num),
+                                stream.GetString().str());
   }
 
   return register_object;




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