Near-infinite loop and crash in Network Browser

If the Beyonwiz doesn't have its Internet enabled and configured, running MENU>Setup>Network>Network browser runs into a near-infinite loop that consumes all available menu and eventually causes a UI crash because it is starved of memory.

If the network isn't set up, when the Network browser runs, it scans the network by running:

nmap -oX - 0.0.0.0/0 -sP 2>/dev/null

and collecting the standard output in a Console instance's result buffer.

When nmap is run with that IP address/mask combination, it scans the whole 4 billion or so addresses in the IPv4 address range, and produces one line of output for each IP address scanned:

<target specification="0.0.0.1" status="skipped" reason="invalid"/>
<target specification="0.0.0.2" status="skipped" reason="invalid"/>
<target specification="0.0.0.3" status="skipped" reason="invalid"/>
<target specification="0.0.0.4" status="skipped" reason="invalid"/>
<target specification="0.0.0.5" status="skipped" reason="invalid"/>

That accumulates in the Console's result buffer until all available memory is consumed. Eventually (generally after some hours) that causes the UI to crash. In the two crash logs I have for this bug, the crash is caused by a SIGSEGV, possibly due to malloc() returning NULL, and the NULL return not being checked.

Replication steps

In MENU>Setup>Network>Network interface, disable all network interfaces. Reboot to make sure that the interfaces are completely disabled.

Remove any cached browser results using:

init 4
rm /etc/enigma2/networkbrowser.cache
init 3

Then MENU>Setup>Network>Network browser to start a network scan. Wait... The "busy" spinner will appear after a while, and may start to run slowly. Eventually the system will crash due to memory starvation and the GUI will restart.

Re-enable the network interfaces and examine the debug log file from the scan for the nmap command and verify that it has the form described above.

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