Jonathan Corbet (pictured above), who is also the editor of the Linux Weekly News website, described in an article how a flaw in the kernel, which was initially discussed on a private mailing list, had been made public with a posting by a developer named Oleg Nesterov.

According to Corbet, the vulnerability in question would permit the running of arbitrary code in kernel mode.

"It seems that the Linux implementation of the ptrace() system call contains a race condition: a traced process's registers can be changed in a way that causes the kernel to restore that process's stack contents to an arbitrary location," he wrote.

Corbet raised the issue in the context of a discussion of other kernel vulnerabilities and criticism, by a security-oriented firm Trustwave, of the way these were handled. The firm claimed that it took nearly three years to patch two flaws, claims which Corbet contested.

But in the case of the vulnerability that he himself cited, Corbet said the bug was known to be a serious one from the outset and that one of the developers who reported it had also created exploit code to demonstrate its severity.

He said that though the public discussion of this bug was nearly a month old at the time of writing - his article appeared on February 19 - and had been discussed for a while before that privately, no distributor had taken a step to issue a fix.

Nesterov works for Red Hat and Corbet quoted another developer as asking why this company had not handled the issue as it should have been.

"Distributors knew about the problem and had time to respond to it — but that response did not happen in a timely manner," Corbet concluded.

"The ptrace() problem will certainly be straightened out in less than three years, but that still may not be a reason for pride. Users should not be left wondering what the situation is (at least) one month after distributors know about a serious vulnerability."