Team for Research in
Ubiquitous Secure Technology

Citation
Suhabe Bugrara, Alex Aiken. "Verifying the Safety of User Pointer Dereferences". Talk or presentation, 12, November, 2008.

Abstract
Operating systems divide virtual memory addresses into kernel space and user space. The interface of a modern operating system consists of a set of system call procedures that may take pointer arguments called user pointers. It is safe to dereference a user pointer if and only if it points into user space. If the operating system dereferences a user pointer that does not point into user space, then a malicious user application could gain control of the operating system, reveal sensitive data from kernel space, or crash the machine. Because the operating system cannot trust user processes, the operating system must check that the user pointer points to user space before dereferencing it. In this paper, we present a scalable and precise static analysis capable of verifying the absence of unchecked user pointer dereferences. We evaluate an implementation of our analysis on the entire Linux operating system with over 6.2 million lines of code with false alarms reported on only 0.05% of dereference sites.

Electronic downloads

• 25%20-%20Bugrara.ppt · application/vnd.ms-powerpoint · 492 kbytes

• HTML

  Suhabe Bugrara, Alex Aiken. <a
  href="http://www.truststc.org/pubs/496.html"
  ><i>Verifying the Safety of User Pointer
  Dereferences</i></a>, Talk or presentation,  12,
  November, 2008.

• Plain text

  Suhabe Bugrara, Alex Aiken. "Verifying the Safety of
  User Pointer Dereferences". Talk or presentation,  12,
  November, 2008.

• BibTeX

  @presentation{BugraraAiken08_VerifyingSafetyOfUserPointerDereferences,
      author = {Suhabe Bugrara and Alex Aiken},
      title = {Verifying the Safety of User Pointer Dereferences},
      day = {12},
      month = {November},
      year = {2008},
      abstract = {Operating systems divide virtual memory addresses
                into kernel space and user space. The interface of
                a modern operating system consists of a set of
                system call procedures that may take pointer
                arguments called user pointers. It is safe to
                dereference a user pointer if and only if it
                points into user space. If the operating system
                dereferences a user pointer that does not point
                into user space, then a malicious user application
                could gain control of the operating system, reveal
                sensitive data from kernel space, or crash the
                machine. Because the operating system cannot trust
                user processes, the operating system must check
                that the user pointer points to user space before
                dereferencing it. In this paper, we present a
                scalable and precise static analysis capable of
                verifying the absence of unchecked user pointer
                dereferences. We evaluate an implementation of our
                analysis on the entire Linux operating system with
                over 6.2 million lines of code with false alarms
                reported on only 0.05% of dereference sites. },
      URL = {http://www.truststc.org/pubs/496.html}
  }
  

Posted by Jessica Gamble on 23 Jan 2009.
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