185 research outputs found
Network centrality, knowledge searching and creativity: The role of domain
This study aims to determine the role of knowledge searching on creativity in the fields of science research and technology development. Creativity is a process of knowledge combination, thus internal and external knowledge searching is important for creativity in both fields, particularly in the open innovation age. However, the nature of the work across these fields is different. While science research aims to solve theoretical problems and generate new knowledge, technology development aims to apply new knowledge to solve practical problems. Compared to science research, technology development has clear task goals, which make it easier to identify the related external knowledge and integrate this knowledge and in turn improve employee creativity. Thus, employees\u27 attention to external knowledge as well as the influence of external knowledge on creativity might be different in the two fields. Results based on an empirical study of 211 employees from science research and 257 employees from technology development showed that external knowledge searching increased employee creativity in the field of technology development but not in science research. Furthermore, employees\u27 centrality in the intra-team problem-solving network moderated the relationship between external knowledge searching and creativity in the science research field. Suggestions about employee creativity management in science and technology fields are discussed
CATTmew: Defeating Software-only Physical Kernel Isolation
All the state-of-the-art rowhammer attacks can break the MMU-enforced
inter-domain isolation because the physical memory owned by each domain is
adjacent to each other. To mitigate these attacks, physical domain isolation,
introduced by CATT, physically separates each domain by dividing the physical
memory into multiple partitions and keeping each partition occupied by only one
domain. CATT implemented physical kernel isolation as the first generic and
practical software-only defense to protect kernel from being rowhammered as
kernel is one of the most appealing targets.
In this paper, we develop a novel exploit that could effectively defeat the
physical kernel isolation and gain both root and kernel privileges. Our exploit
can work without exhausting the page cache or the system memory, or relying on
the information of the virtual-to-physical address mapping. The exploit is
motivated by our key observation that the modern OSes have double-owned kernel
buffers (e.g., video buffers and SCSI Generic buffers) owned concurrently by
the kernel and user domains. The existence of such buffers invalidates the
physical kernel isolation and makes the rowhammer-based attack possible again.
Existing conspicuous rowhammer attacks achieving the root/kernel privilege
escalation exhaust the page cache or even the whole system memory. Instead, we
propose a new technique, named memory ambush. It is able to place the
hammerable double-owned kernel buffers physically adjacent to the target
objects (e.g., page tables) with only a small amount of memory. As a result,
our exploit is stealthier and has fewer memory footprints. We also replace the
inefficient rowhammer algorithm that blindly picks up addresses to hammer with
an efficient one. Our algorithm selects suitable addresses based on an existing
timing channel.Comment: Preprint of the work accepted at the IEEE Transactions on Dependable
and Secure Computing 201
PThammer: Cross-User-Kernel-Boundary Rowhammer through Implicit Accesses
Rowhammer is a hardware vulnerability in DRAM memory, where repeated access
to memory can induce bit flips in neighboring memory locations. Being a
hardware vulnerability, rowhammer bypasses all of the system memory protection,
allowing adversaries to compromise the integrity and confidentiality of data.
Rowhammer attacks have shown to enable privilege escalation, sandbox escape,
and cryptographic key disclosures. Recently, several proposals suggest
exploiting the spatial proximity between the accessed memory location and the
location of the bit flip for a defense against rowhammer. These all aim to deny
the attacker's permission to access memory locations near sensitive data. In
this paper, we question the core assumption underlying these defenses. We
present PThammer, a confused-deputy attack that causes accesses to memory
locations that the attacker is not allowed to access. Specifically, PThammer
exploits the address translation process of modern processors, inducing the
processor to generate frequent accesses to protected memory locations. We
implement PThammer, demonstrating that it is a viable attack, resulting in a
system compromise (e.g., kernel privilege escalation). We further evaluate the
effectiveness of proposed software-only defenses showing that PThammer can
overcome those.Comment: Preprint of the work accepted at the International Symposium on
Microarchitecture (MICRO) 2020. arXiv admin note: text overlap with
arXiv:1912.0307
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