%e in /proc/sys/kernel/core_pattern and empty current->comm

[Earl Chew <echew@ixiacom.com>]

It is possible to set /proc/sys/kernel/core_pattern to %e:

	echo '%e' > /proc/sys/kernel/core_pattern


A couple of interesting effects:

a. Cores will tend to try to overwrite the executable.

    Is this considered an issue ?


b. Apparently it seems possible to set current->comm to be empty:

	prctl(PR_SET_NAME, "", 0, 0, 0);

   No core dump is generated since the resulting corename is empty,
   and filp_open() fails.

   Is this considered a defect, or potential security concern ?


c. Consequential to (b), setting /proc/sys/kernel/core_pattern to empty
   and /proc/sys/kernel/core_uses_pid to zero universally prevents
   core dumps.

   I'm wondering if this behaviour is provided intentionally.


Earl