Messages in this thread | | | Date | Wed, 3 Feb 1999 13:50:52 +0100 (MET) | From | Richard Kail <> | Subject | Re: [patch] /proc race fixes for 2.2.1 (fwd) |
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Hello !
There seems to be anoter /proc race in the 2.2.1 linux kernel. I will explain this with an example:
modprobe coda.o # will load coda.o as dynamically module # the kernel will create a /proc/fs/coda directory # on the fly.
cd /proc/fs/coda # make shell chdir("/proc/fs/coda")
rmmod coda.o # works ! (shouldn't)
ls -l # generate a oops.
after this, the coda.o module seems not to work at all. Maybe this is a systematic problem of more than one driver. I am not a kernel hacker, so I can't check all kernel modules for this kind of problem.
Since a user can control the whole process I think has security implications.
A user can trigger a "modprobe module" command using the kerneld (oh, its called kmod now...) mechanism.
A user can chdir /proc/fs/coda.
If the system has implemented the cron job as suggested in linux/Documentation/kmod.txt the user has just to wait with wd=/proc/fs/code to crash the system.
Kind regards, Richard
------ "One day, computer power will eventually outstrip demand, and OS engineers will be free to use friendly languages like LISP again.. until then, I think we're stuck with C." -- Oliver Xymoro
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