Submission + - Secretly monopolizing the CPU without being root
An anonymous reader writes: This year's
Usenix security symposium
includes a
paper
that implements a "cheat" utility, which allows any non-privileged user to
run his/her program, e.g., like so
cheat 99% program
thereby insuring that the programs would get 99% of the CPU cycles, regardless of the presence of any other applications in the system, and in some cases (like Linux), in a way that keeps the program invisible from CPU monitoring tools (like 'top'). The utility exclusively uses standard interfaces and can be trivially implemented by any beginner non-privileged programmer. Recent efforts to improve the support for multimedia applications make systems more susceptible to the attack. All prevalent operating systems but Mac OS X are vulnerable, though by this kerneltrap story, it appears that the new CFS Linux scheduler attempts to address the problem that were raised by the paper.
cheat 99% program
thereby insuring that the programs would get 99% of the CPU cycles, regardless of the presence of any other applications in the system, and in some cases (like Linux), in a way that keeps the program invisible from CPU monitoring tools (like 'top'). The utility exclusively uses standard interfaces and can be trivially implemented by any beginner non-privileged programmer. Recent efforts to improve the support for multimedia applications make systems more susceptible to the attack. All prevalent operating systems but Mac OS X are vulnerable, though by this kerneltrap story, it appears that the new CFS Linux scheduler attempts to address the problem that were raised by the paper.