Messages in this thread | | | Subject | Re: [PATCH] Add a /proc/self/exedir link | From | (Eric W. Biederman) | Date | Fri, 07 Apr 2006 13:10:26 -0600 |
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Andreas Schwab <schwab@suse.de> writes:
> Neil Brown <neilb@suse.de> writes: > >> On Thursday April 6, tony.luck@gmail.com wrote: >>> > > I have concerns about security policy ... >>> > >>> > I'm not sure I understand. Only if you run that program, and if you >>> > don't have access to the intermediate directory, how do you run it? >>> >>> It leaks information about the parts of the pathname below the >>> directory that you otherwise would not be able to see. E.g. if >>> I have $HOME/top-secret-projects/secret-code-name1/binary >>> where the top-secret-projects directory isn't readable by you, >>> then you may find out secret-code-name1 by reading the >>> /proc/{pid}/exedir symlink. >> >> But we already have /proc/{pid}/exe which is a symlink to the >> executable, thus exposing all the directory names already. > > Neither of which should be readable by anyone but the owner of the > process, which is the one who was able to read the secret directory in the > first place.
In most cases. It is possible you got the executable through file descriptor passing and the like.
The security check in -mm allows anyone who may ptrace the process to have read access. In 2.6.17-rc1 the check is still the owner of the process and anyone with CAP_DAC_ACCESS may read or use the link.
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