* Flaw affects kernel memory of processors made in last decade
* Patch causes Linux, Windows systems to slow - report
* AMD says its chips not affected by the flaw
* Intel shares fall 3 pct; AMD up 7 pct in pre-market trade
FRANKFURT, Jan 3 (Reuters) - A design flaw has been found in microprocessors made by Intel Corp that requires updates to computer operating systems, a tech publication reported, adding that the fix causes the chips to operate more slowly.
The defect affects the so-called kernel memory on Intel processor chips manufactured over the past decade, The Register reported, citing unnamed programmers, and the flaw allows users of normal applications to discern the layout or content of protected areas on the chips.
That could make it possible for hackers to exploit other security bugs or, worse, expose secure information such as passwords, thus compromising individual computers or even entire server networks.
Intel and Microsoft did not immediately respond to emailed requests for comment sent during European working hours.
Shares in Intel fell by more than 3 percent in pre-market trading following the report.
The Register said programmers for the Linux open-source operating system were working to overhaul the affected memory areas, while Microsoft Corp was expected to issue a Windows patch next Tuesday after circulating test fixes towards the end of 2017.
"Crucially, these updates to both Linux and Windows will incur a performance hit on Intel products," The Register wrote (http://bit.ly/2CsRxkj).
"The effects are being benchmarked, however we are looking at a ballpark figure of a five to 30 percent slowdown, depending on the task and the processor model."
Competing chip maker AMD has told Linux developers by email that its chips are not vulnerable to the types of attacks that the fix for the Intel chip is intended to address by isolating the kernel memory, The Register said.
Shares in AMD jumped more than 7 percent in premarket trade after The Register report on Intel.
Further, the bug is likely to affect major cloud computing platforms such as Amazon EC2, Microsoft Azure and Google Compute Engine, according to one software blogger cited by The Register.
Microsoft Azure is due to undergo a maintenance reboot on Jan. 10 while Amazon Web Services has also advised customers via email to expect a major security update this Friday.
The Register also said that similar operating systems, such as Apple's 64-bit macOS operating system, would need to be updated. (Reporting by Douglas Busvine and Jim Finkle; Editing by Susan Fenton)