I came across this in a Bugzilla report. As described in the commit message, it may pollute the system entropy pool. Although the microcode fix is already included in the latest AGESA release from earlier this year—so systems with updated BIOS firmware should be unaffected, not all users regularly update their BIOS, and not all vendors have distributed the patch.

Given that, I think this issue is still worth taking a closer look.

emaste added a reviewer: kib.Thu, Apr 9, 3:35 PM

emaste added a subscriber: emaste.

In D56332#1288887, @aokblast wrote:

I came across this in a Bugzilla report. As described in the commit message, it may pollute the system entropy pool. Although the microcode fix is already included in the latest AGESA release from earlier this year—so systems with updated BIOS firmware should be unaffected, not all users regularly update their BIOS, and not all vendors have distributed the patch.

Given that, I think this issue is still worth taking a closer look.

Per https://www.amd.com/en/resources/product-security/bulletin/amd-sb-7055.html (and the linked thread), only rdseed with a 16-bit or 32-bit operand is affected, but here it's a 64-bit output.

In D56332#1288903, @markj wrote:

In D56332#1288887, @aokblast wrote:

I came across this in a Bugzilla report. As described in the commit message, it may pollute the system entropy pool. Although the microcode fix is already included in the latest AGESA release from earlier this year—so systems with updated BIOS firmware should be unaffected, not all users regularly update their BIOS, and not all vendors have distributed the patch.

Given that, I think this issue is still worth taking a closer look.

Per https://www.amd.com/en/resources/product-security/bulletin/amd-sb-7055.html (and the linked thread), only rdseed with a 16-bit or 32-bit operand is affected, but here it's a 64-bit output.