#215 HexEditor 0.9.5 resource exhaustion

[Ariel Poliak]

The HexEditor plugin (0.9.5 Unicode) will consume all available system resources under the following conditions:
1. The OS is WIndows 7 (may also occur in Vista/8)
2. The DLL is placed on the global plugins directory (e.g. "c:\Program Files (x86)\Notepad++\Plugins" )
3. Per-user plugins are disabled (default)
4. Notepad++ has not been used by the current user (e.g. "%APPDATA%\Notepad++\plugins" does not exist)

When Notepad++.exe is launched, it will start loading plugins.
Once the HexEditor DLL is loaded, it will start an endless loop of CreateFile() calls with "%APPDATA%\Notepad++\plugins" as the target.
(this is shown in the attached ProcMon log file)

However, by manually creating the "%APPDATA%\Notepad++\plugins" directory before launching Notepad++.exe, a message box stating "Unknown Exception" appears, but once acknowledged, the plugin loads successfully and Notepad++ behaves as expected.

Re-opening Notepad++ again shows no message box, and Notepad++ behaves as expected

[Ariel Poliak]

Log files are too large for upload to SourceForge,
They have been uploaded here: https://www.dropbox.com/sh/znxvdv11m7r532m/ULIZwgQuAs

"cleanslate.pml" - first run, post-installation
"firstaftermd.pml" - second run, after manually creating per-user plugins directory
"nextaftermd.pml" - third run, after closing second run.

[Ariel Poliak]

A quick glance at the plugin's source leads me to believe that the issue may lie in the loadSettings() function within NppPlugins/HexEditor/src/Hex.cpp

[Ariel Poliak]

lines 338-342 are responsible:

*_tcsrchr(configPath, '\\') = NULL;
do {
vPaths.push_back(configPath);
*_tcsrchr(configPath, NULL) = NULL;
} while (::PathFileExists(configPath) == FALSE);
===
The code above is supposed to add directory names to the vPaths vector in such a way that when the loop in lines 344-349 executes, the proper directory structure will be created in the correct order.

However, the code in line 341, «*_tcsrchr(configPath, NULL) = NULL;», does not strip out a directory level. It replaces the null string delimiter with another null delimiter.
This is what causes the infinite loop.

If the code read «*_tcsrchr(configPath, '\\') = NULL;» instead (like in line 338), the function would work as expected.

[Ariel Poliak]

Forgot to mention, the reason for resource exhaustion is the vPaths.push_back() call within the infinite loop.

[Ariel Poliak]

Patch that implements fix described in comment #3

[Ariel Poliak]

Patch with fix added to this artifact.

[jskywalker]

When will this fix be in the latest version of Notepad++

The message than HexEditor-plugin is 'unstable' is useless, as long as you simply can re-install it.

[M. Buecher]

This bug is still present with Hex Editor 0.9.5 and Notepad++ 6.8.8.

The workaround is to issue the following command:
mkdir "%APPDATA%\Notepad++\plugins\config"

[jskywalker]

If this workaround is so simple,
and '%APPDATA%\Notepad++\plugins\config' being under the control of Notepad++

i would make a vote to implement the creation if this directory a.s.a.p.
(checking and, if needed,, creation upon start of Notepad++)