Transient faults in safety-critical computer-based systems represent a major issue for guaranteeing correct system behaviour. Fault injection is a commonly used method to evaluate the sensitivity of such systems. This paper presents a fault injection tool, called KITO, to evaluate the effects of faults in memory containing data structures belonging to a Unix-based Operating System and, in particular, elements linked to resource synchronization management. An experimental analysis was conducted on a large set of memory elements of the Operating System itself, while the system was subject to stress from benchmark programs that use different elements of the Linux kernel. Experimental results show that synchronization aspects of the kernel are susceptible to a significant set of possible errors ranging from performance degradation to failure in successfully completing the benchmark application. (C) 2016 Elsevier Ltd. All rights reserved.