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From: peter@thirdi.UUCP (Peter Rowell)
Newsgroups: comp.unix.wizards
Subject: Down in the Dumps (a true story)
Date: 19 May 88 22:13:13 GMT
Organization: Third Eye Software, Menlo Park, CA
If the following command does not look Evil to you, then read on....
dump 0usf /dev/rmt0 /dev/rrf0g
I post this to the net in the hopes it will save someone else from
nailing themselves to the cross like I did. I am sure that more than
a few people will read this and say.
"Oh sure, *I* knew that's what would happen. Why didn't you:
(a) RTFM (read the friendly manual) (b) be more careful."
Well, actually, I *did* just RTFM and then I made one simple little
error and Murphy stepped all over my file system.
In case you haven't already figured it out, the command in
question (dump 0usf /dev/rmt0 /dev/rrf0g) will wipe out the
file system residing on device /dev/rrf0g! (Yes, it really did...)
The problem is that the "s" flag is looking for a size specification for
the tape (which I accidently left out). It apparently ate "/dev/rmt0"
and decided that it liked that just fine. Next, the "f" flag says "Oh
boy! I get to do the dump TO /dev/rrf0g". Now, it would have been nice
if dump had complained that I had not told it what device to dump FROM,
but Nnnoooooo, the manual says:
" ... If no arguments are given, the key is assumed to be 9u and a
default file system is dumped to the default tape. ..."
^^^^^^^^^^^^^^^^^^^
The default on my system (an ISI box running 4.3) is /dev/rsd0g. Since
this is a valid device on my system, dump promptly started dumping /usr
all over rrf0fg.
I saw right away that I had left the length off and interrupted the dump.
When I started it up again (with the length) it informed me that the
super-block was now caca and that I should run fsck with the -b switch.
I did this with -b 32 and -b 11600 and -b etc. etc. etc. sigh.
(Through no fault of my own, we did have a recent dump to restore from.)
In conclusion:
I *know* that being root is dangerous. I just never expected that
I could *create* a dead file system by using dump!
I personally would like to see dump modified along these lines:
1. Not default *anything* (except, perhaps, dump TO tape).
2. Be pickier about what a valid numerical value is.
3. Require confirmation for dangerous target devices.
(Such as mounted file systems or things in /etc/fstab.)
On Tuesday, May 18, The Boston Globe business section included a column
(probably syndicated) called "Your Computer" written by John J. Xenakis
(1610 Worcester Road, Suite 629A, Framingham, MA 01701) that gave a
decent overview of the virus phenomena.
The same issue of the Globe (I think, I can't find it now) had an article
on a virus that attacked the newsroom computers at the Providence (RI) Journal.
This morning, WBUR radio broadcast a story on that virus. These notes
were scribbled at the time:
In an instant, a reporter lost weeks of work. Their systems programmer
used a special program to look at the disk. He found "welcome to the
dungeon — beware of this virus" and three telephone numbers in Pakistan.
One of them reached a person who expressed suprise that the virus had
gotten that far.
Fred Cohen at the University of Cincinnati said that the virus reached
Delaware [University of?] last year. At least three others are on the
loose. The best advice is don't share disks. Cohen also noted that
the Macbug virus got into "legitimate distribution channels" so shrink-
wrapped software might not be safe. Also "viruses can mutate."
The Journal's virus was found on disks in their news bureaus and on
their employees' home computers. Their systems programmer is afraid
that, although they've gone through all their disks to elminate it,
"a copy might be lurking in some desk drawer."
This particular virus infects IBM PC's and clones. You might consider
buying an anti-viral program, but at least one is itself infected.
WBUR local news stories are often picked up by NPR, so you might keep an
ear open to All Things Considered and/or Weekend Edition.
This particular virus isn't new to RISKS readers. What is interesting,
however, is that the part of the general public that reads the business
section and/or listens to public radio news is getting a reasonable education
in this field.
[The NY Times of 25 May 1988 has an article in THE MEDIA BUSINESS, p.C18.
The virus made its appearance when a financial reporter, Froma Joselow,
saw the message "disk error" on her computer screen after she
unsuccessfully tried to print out a copy of a news article she had been
writing. There was a virus program on her floppy, which caused this
message on the screen: "Welcome to the Dungeon... Beware of this VIRUS.
Contact us for vaccination." The message included an address and phone
number of Brain Computer Services... PGN]
PS: how can virus [programs] mutate?
[Self-mutating, e.g, by adapting to their environments. PGN]
Attempts to influence stock market trading patterns by taxing short-term gains at higher rates aren't likely to have much effect. Apart from the remoteness of the tax hit, bear in mind that the traders who most influence the stock market are those who manage the huge pension funds, which don't pay any income tax. David Sherman dave@lsuc.uucp (Canadian tax lawyer)
It is quite frightening to contemplate a financial transaction system that can be brought down by application of a bandaid to a paper cut on the thumb--let alone the unthinkableness of losing a thumbnail.
There seems to have been a fair amount of high horsemanship in the correspondance to date on the Hinsdale fire. Perhaps it shows one of the biggest potential risks associated with a disaster of this sort, namely the oversimplified fixes that people not in a position to make a full appraisal are likely to push on anyone who will listen. The remark about the lack of operators in a modern central office is a case in point. I wonder how many people know the size of the installation necessary to allow manual operators to handle a large enough fraction of the traffic offered by tens of thousands of subscribers to make any difference? In any case, such equipment was typically made of beautifully polished wood, and would burn at least as well as an electronic switch, although the smoke might be less toxic. A good deal of criticism was leveled at cost cutting measures. The phone companies have been under intense pressure to cut costs. The divestiture decree was meant to cut costs by introducing competition. As models of efficiency the phone companies may have been matched only by the federal government. Some recent measures may have been misdirected, and much more improvement remains possible. However, there was no widespread campaign to pay more for more reliable phone service. Hopefully, the hub concept will be revised to provide diverse routing from end offices to the rest of the network, in spite of the cost and network management problems involved. Perhaps cellular phones will be recognized as a backup to the main network, with base station equipment separately located and trunking to the land network carried over diverse routes. Policies of this sort are only likely to be instituted if the cost is included in the rate base, and then only if there is widespread public acceptance of the cost. Another significant risk which undoubtedly exists in many situations is the tendency for increases in computing power to decrease modular redundancy. That which is cost effective is not necessarily cheap in small doses. The phone system is highly distributed, but the parts may not function well independantly. Each part of the system may strike the casual observer as large in itself, not a small part of a whole. In fact, each part is likely to be duplicated, separately powered, and and redundantly connected to duplicated sets of other key components. For performance and logistic reasons, the duplicated parts are not likely to be geographically dispersed. In any case, the wires from your phone just go to one switch building, so the benefits of dispersal of the switch remain academic. We can all hope for lessons from the high level planning down to the the day to day operational procedures that allowed the delay in summoning the fire department.
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