Messages in this thread |  | | Date | Tue, 17 Dec 1996 10:33:33 +1100 (EST) | From | Dave Cole <> | Subject | Re: security implications (was Re: Proposal: restrict link(2)) |
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On Mon, 16 Dec 1996, Keith Rohrer wrote:
> > > So what have I learned: > > o /tmp and /home and /usr should be on different partitions > If you can manage it. You'd likely want to make /home separate to save > hassle when upgrading/re-installing the system. /tmp being on its own > filesystem can prevent some denial of service attacks.
Talking about denial of service attacks using /tmp; we did it to ourselves accidentally on a SunOS machine. We ran Adobe Distiller on a PostScript file that had 100,000 pages. We noticed sometime the next day that the machine had slowed to a crawl.
It turns out that Distiller was creating a file in /tmp for every page processed. We had about 100,000 zero length files in /tmp. Under SunOS, directories never shrink, so we had to remake the file system to get back normal performance.
I suppose we could have avoided the mkfs if we had: # mount /dev/sd4e /.tmpfs # mkdir /.tmpfs/tmp # ln -s /.tmpfs/tmp /tmp
Then we could have just created a new directory in /.tmpfs and pointed the symlink at the new directory.
I have not bothered to check if ext2fs shrinks directories, maybe this "technique" would work on Linux too.
- Dave
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