Messages in this thread |  | | From | (Miquel van Smoorenburg) | Subject | Re: /proc/<pid>/mem unreadable (was strace and linux 1.3.97) | Date | Mon, 6 May 1996 20:21:04 +0200 (MET DST) |
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In article <96May3.101144+0100met_dst.2218-305+20@work.smurf.noris.de>, Matthias Urlichs <smurf@smurf.noris.de> wrote: >In linux.dev.kernel, article <199605021038.FAA16498@caffeine.io.com>, > "James H. Cloos Jr." <cloos@jhcloos.com> writes: >> >> Seems to me that the answer, then, is to have /prov/<pid>/mem mod 600 >> and owned by the euid of the process, rather than owned by the uid >> that ran it. Linus? >> >No, that woon't work, for when the setuid program does a >seteuid(getuid()) >exec(user_program) > >it's still vulnerable between these two calls. > >The _only_ workable solution for this is to invalidate the /proc/###/mem >inode when the process in question calls exec().
As you might have seen, it is fixed in 1.3.98. Access to /proc/###/mem is only allowed if the process has been PTRACE_ATTACHed to by the process that tries to read/write/mmap to it.
Mike. -- + Miquel van Smoorenburg + Cistron Internet Services + Living is a | | miquels@cistron.nl (SP6) | Independent Dutch ISP | horizontal | + miquels@drinkel.ow.org + http://www.cistron.nl/ + fall +
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