CVE-2026-31628 PUBLISHED

x86/CPU: Fix FPDSS on Zen1

Assigner: Linux
Reserved: 09.03.2026 Published: 24.04.2026 Updated: 25.04.2026

In the Linux kernel, the following vulnerability has been resolved:

x86/CPU: Fix FPDSS on Zen1

Zen1's hardware divider can leave, under certain circumstances, partial results from previous operations. Those results can be leaked by another, attacker thread.

Fix that with a chicken bit.

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from f7f3dc00f61261cdc9ccd8b886f21bc4dffd6fd9 to ed7a3a246309ccc807238f1b4f159ee6d37ff9c4 (excl.)
  • affected from f7f3dc00f61261cdc9ccd8b886f21bc4dffd6fd9 to 0548529af20e68c6552817834b766646dd3bd7a7 (excl.)
  • affected from f7f3dc00f61261cdc9ccd8b886f21bc4dffd6fd9 to 1272cfedf4cd1019ddf583917a99b62f2d3645bb (excl.)
  • affected from f7f3dc00f61261cdc9ccd8b886f21bc4dffd6fd9 to 91f02726b2203b71545713ecb7fb006e60a2d66f (excl.)
  • affected from f7f3dc00f61261cdc9ccd8b886f21bc4dffd6fd9 to b731aca06387b195058a9f6449a03b62efa1bd10 (excl.)
  • affected from f7f3dc00f61261cdc9ccd8b886f21bc4dffd6fd9 to ad17f07e95e6e8505e2153e5b391f0d27eacce25 (excl.)
  • affected from f7f3dc00f61261cdc9ccd8b886f21bc4dffd6fd9 to e6af5286efe5a56128b34032572c9ce9ebeccda3 (excl.)
  • affected from f7f3dc00f61261cdc9ccd8b886f21bc4dffd6fd9 to 546785c719418c6166834a47e372a88f5f7ae893 (excl.)
  • Version 5abd1583e06b3963e5c9d915760367de86808b78 is affected
  • Version 4ba461d426490b6ed7e8298c4d3b7a13aa5d2686 is affected
  • Version 5a63725cd18fcee2af6ec46ccb856b64ad3077b4 is affected
Vendor Linux
Product Linux
Versions Default: affected
  • Version 4.14 is affected
  • unaffected from 0 to 4.14 (excl.)
  • unaffected from 5.10.253 to 5.10.* (incl.)
  • unaffected from 5.15.203 to 5.15.* (incl.)
  • unaffected from 6.1.169 to 6.1.* (incl.)
  • unaffected from 6.6.135 to 6.6.* (incl.)
  • unaffected from 6.12.82 to 6.12.* (incl.)
  • unaffected from 6.18.23 to 6.18.* (incl.)
  • unaffected from 6.19.13 to 6.19.* (incl.)
  • unaffected from 7.0.1 to 7.0.* (incl.)

References