Messages in this thread | | | Date | Tue, 27 Jan 2015 10:23:23 +0300 | From | Cyrill Gorcunov <> | Subject | Re: [RFC][PATCH v2] procfs: Always expose /proc/<pid>/map_files/ and make it readable |
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On Mon, Jan 26, 2015 at 10:50:23PM -0800, Andrew Morton wrote: > On Tue, 27 Jan 2015 09:46:47 +0300 Cyrill Gorcunov <gorcunov@gmail.com> wrote: > > > > There's one other problem here: we're assuming that the map_files > > > implementation doesn't have bugs. If it does have bugs then relaxing > > > permissions like this will create new vulnerabilities. And the > > > map_files implementation is surprisingly complex. Is it bug-free? > > > > I didn't find any bugs in map-files (and we use it for long time already) > > so I think it is safe. > > You've been using map_files the way it was supposed to be used so no, > any bugs won't show up. What happens if you don your evil black hat > and use map_files in ways that weren't anticipated? Attack it?
Hard to say, Andrew. If I found a way to exploit this feature for bad purpose for sure I would patch it out. At the moment I don't see any. Touching another process memory via file descriptor allows one to modify its contents but you have to be granted ptrace-may-access which i consider as enough for security.
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