OS-level fix may lead to sharp reduction in CPU performance

Advanced Micro Devices (AMD), the world’s second-biggest supplier of x86-based microprocessors, has seen its share price rise more than 12% since close of trading on Friday, as scattered details emerge of a critical flaw in chips developed by market leader, Intel.

With 2018 barely out of the gate, the internet has been buzzing with reports of a chip-level security bug affecting Intel CPUs. All computers built around the Santa Clara tech giant’s x86-based microprocessors are thought to be affected, including those running Windows, Linux, and macOS.

Although the full details of the hardware bug are still under embargo, reports from Python Sweetness and The Register have attempted to piece together the exact nature of the flaw, which is thought to allow normal user programs to access some of the contents of the protected kernel memory.

“At worst, the hole could be abused by programs and logged-in users to read the contents of the kernel’s memory,” says The Register’s John Leyden. “The kernel’s memory space is hidden from user processes and programs because it may contain all sorts of secrets, such as passwords, login keys, files cached from disk, and so on.”

It’s understood that the vulnerability cannot be mitigated with a microcode update, and instead requires a patch at the OS level. Linux patches have already been rolled out, and Microsoft is expected to address the bug over the coming days. Apple’s 64-bit macOS is also thought to need an update.

The main source of discontent among the IT community, however, is that the posited fix – which splits kernel and user spaces to prevent information leak – may lead to a sharp drop in CPU performance.

“We’re looking at a ballpark figure of five to 30% slowdown, depending on the task and processor model,” The Register said.

As tech observers await further details of the Intel chip flaw, AMD’s NASDAQ share price hit $11.63 in early Wednesday trading, up 12.3% on Friday’s closing price of $10.28.