> Through get_task_comm() and many direct uses of task->comm in the kernel, > it is possible for escape codes and other non-printables to leak into > dmesg, syslog, etc. In the worst case, these strings could be used to > attack administrators using vulnerable terminal emulators, and at least > cause confusion through the injection of \r characters. > > This patch sanitizes task->comm to only contain printable characters > when it is set. Additionally, it redefines get_task_comm so that it is > more obvious when misused by callers (presently nothing was incorrectly > calling get_task_comm's unsafe use of strncpy). > > Signed-off-by: Kees Cook <kees.cook@xxxxxxxxxxxxx> I've reviewed this patch briefly, Here is my personal concern... On Linux, non-printable leaking is fundamental, only fixing task->comm doesn't solve syslog exploit issue. Probably all /proc/kmsg user should have escaping non-pritables code. However, task->comm is one of most easy injection data of kernel, because we have prctl(PR_SET_NAME), attacker don't need root privilege. So, conservative assumption seems guard from crappy fault. Plus, this patch is very small and our small TASK_COMM_LEN lead that we don't need big performance concern. So, I don't find demerit in this proposal. but I'm not security specialist, it's only personal thinking. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
