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Comment Rowhammer in MemTest86 & on Slashdot (Score 5, Informative) 180

by PassMark (#49222339) Attached to: Exploiting the DRAM Rowhammer Bug To Gain Kernel Privileges

It is worth noting that the row hammer issue isn't new. It as been known about for some time. Including this old Slashdot post
http://hardware.slashdot.org/s...

There has been an implementation of row hammer testing in MemTest86 V6.0 for over 6 months now as well. MemTest86 implements just the single sided hammer, whereas Google used a double sided hammer.
http://www.memtest86.com/
While the double hammer might produce more RAM errors, this pattern of memory accesses isn't very likely to occur in real life software. So is of limited use as a RAM reliability test.

What is new in this report is the fact that they manipulated the RAM bit flips to turn them into an exploit. Something that was previously speculated on but considered too hard to implement.

What they didn't show however is any results from desktop machines. All their testing was on laptops. In fact they state, "We also tested some desktop machines, but did not see any bit flips on those". So the problem isn't as grave as it might at first appear. They speculate that ECC RAM blocks the bit flips and this has also been the experience with MemTest86, most (but not all) of the flips are single bit flips, which ECC would correct.

Disclaimer: I'm one of the MemTest86 developers.

Comment Rowhammer in MemTest86 & on Slashdot (Score 1) 2

by PassMark (#49221673) Attached to: Exploiting the DRAM Rowhammer Bug to Gain Kernel Privileges

It is worth noting that the row hammer issue isn't new. It as been known about for some time. Including this old Slashdot post
http://hardware.slashdot.org/s...

There has been an implementation of row hammer testing in MemTest86 V6.0 for over 6 months now as well. MemTest86 implements just the single sided hammer, whereas Google used a double sided hammer.
http://www.memtest86.com/
While the double hammer might produce more RAM errors, this pattern of memory accesses isn't very likely to occur in real life software. So is of limited use as a RAM reliability test.

What is new in this report is the fact that they manipulated the RAM bit flips to turn them into an exploit. Something that was previously speculated on but considered too hard to implement.

What they didn't show however is any results from desktop machines. All their testing was on laptops. In fact they state, "We also tested some desktop machines, but did not see any bit flips on those". So the problem isn't as grave as it might at first appear. They speculate that ECC RAM blocks the bit flips and this has also been the experience with MemTest86, most of the flips are single bit flips, which ECC would correct.

Submission + - Exploiting the DRAM Rowhammer Bug to Gain Kernel Privileges (blogspot.com) 2

Submitted by netelder
netelder writes: “Rowhammer” is a problem with some recent DRAM devices in which repeatedly accessing a row of memory can cause bit flips in adjacent rows. We tested a selection of laptops and found that a subset of them exhibited the problem. We built two working privilege escalation exploits that use this effect. One exploit uses rowhammer-induced bit flips to gain kernel privileges on x86-64 Linux when run as an unprivileged userland process. When run on a machine vulnerable to the rowhammer problem, the process was able to induce bit flips in page table entries (PTEs). It was able to use this to gain write access to its own page table, and hence gain read-write access to all of physical memory.

Submission + - Universal Big Bang Lithium Deficit Confirmed

Submitted by Anonymous Coward
An anonymous reader writes: New observations of the star cluster Messier 54 show that it is just as deficient in lithium as our own galaxy, furthering a mystery about the element's big bang origins. "Most of the light chemical element lithium now present in the Universe was produced during the Big Bang, along with hydrogen and helium, but in much smaller quantities. Astronomers can calculate quite accurately how much lithium they expect to find in the early Universe, and from this work out how much they should see in old stars. But the numbers don’t match — there is about three times less lithium in stars than expected. This mystery remains unsolved, despite several decades of work."

Submission + - WD announces 8TB, 10TB helium hard drives (computerworld.com)

Submitted by Lucas123
Lucas123 writes: Western Digital's HGST subsidiary today announced it's shipping its first 8TB and the world's first 10TB helium-filled hard drive. The 3.5-in, 10TB drive also marks HGST's first foray into the use of singled magnetic recording technology, which Seagate announced it began using last year. Unlike standard perpendicular magnetic recording (PMR), where data tracks rest side by side, SMR overlaps the tracks on a platter like shingles on a roof, thereby allowing a higher areal density. Seagate has said SMR technology will allow it to achieve 20TB drives by 2020. That company has yet to use helium, however. HGST said its use of hermetically-sealed helium drives reduces friction among moving drive components and keeps dust out. Both drives use a 7-platter configuration with a 7200 RPM spindle speed. The company said it plans to discontinue its production of air-only drives by 2017, replacing all data center models with helium drives.

Comment Newer LED lights known to cause interference (Score 2) 158

by PassMark (#46208113) Attached to: L.A. Building's Lights Interfere With Cellular Network, FCC Says

After a bunch of anecdotal reports we did some measurements of radio interference caused by LED lighting (and the power supplies included in these globes).

Most were OK, but there are a bunch that spray out a large amount of broad band interference. Some spectrum graphs are here showing a few lights in their on and off states.
http://www.ledbenchmark.com/fa...

Interference was seen in the digital radio bands, FM radio, DAB bands, everywhere really. So the only thing surprising about this post is the lack of publicity the problem has been given to date.

Comment Summary is wrong (Score 2) 218

by PassMark (#44838129) Attached to: It's Official: Voyager 1 Is an Interstellar Probe

Summary appears to be wrong.
"...were able to deduce that Voyager was traveling through a less dense medium — i.e. interstellar space."

Interstellar space is apparently 40 times more dense than space in the solar system. The solar wind pushes the particles back to the edge of the solar system, making the plasma more dense at the edge (not less dense).

To quote from NASA
http://www.jpl.nasa.gov/news/news.php?release=2013-277
"Voyager 1's plasma wave instrument detected the movement. The pitch of the oscillations helped scientists determine the density of the plasma. The particular oscillations meant the spacecraft was bathed in plasma more than 40 times denser than what they had encountered in the outer layer of the heliosphere. Density of this sort is to be expected in interstellar space."

Submission + - NASA: Voyager-1 has not yet left the solar system (nasa.gov)

Submitted by skade88
skade88 writes: From the JPL's Voyager's team blog: "The Voyager team is aware of reports today that NASA's Voyager 1 has left the solar system," said Edward Stone, Voyager project scientist based at the California Institute of Technology, Pasadena, Calif. "It is the consensus of the Voyager science team that Voyager 1 has not yet left the solar system or reached interstellar space. In December 2012, the Voyager science team reported that Voyager 1 is within a new region called 'the magnetic highway' where energetic particles changed dramatically. A change in the direction of the magnetic field is the last critical indicator of reaching interstellar space and that change of direction has not yet been observed."

To learn more about the current status of the Voyager mission, visit: http://www.jpl.nasa.gov/news/news.php?release=2012-381

The Voyager spacecraft were built and continue to be operated by NASA's Jet Propulsion Laboratory, in Pasadena, Calif. Caltech manages JPL for NASA. The Voyager missions are a part of NASA's Heliophysics System Observatory, sponsored by the Heliophysics Division of the Science Mission Directorate at NASA Headquarters in Washington.

Comment Surprisingly poor quality images (Score 1) 42

by PassMark (#39448119) Attached to: Elementary School Kids Explore the Moon At Close Range

I don't get it.
Why spend $375 million sending a camera to the moon only to return such poor quality images?

I looked a dozens of them, they all seem small, grainy, out of focus and black and white. (of course the moon being mostly grey might explain this last point)

Couldn't they afford a better camera? My smartphone would have done a better job.

Apple Orders 10 Million Tablets? 221

Posted by ScuttleMonkey from the pricepoint-better-be-right dept.
Arvisp writes "According to a blog post by former Google China president Kai-Fu Lee, Apple plans to produce nearly 10 million tablets in the still-unannounced product's first year. If Lee's blog post is to be believed, Apple plans to sell nearly twice as many tablets as it did iPhones in the product's first year."

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