github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-05-28 00:53:34 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

x86/bugs: Fix SRSO reporting on Zen1/2 with SMT disabled

Browse Source 
1f4bb068b4 ("x86/bugs: Restructure SRSO mitigation") does this:

  if (boot_cpu_data.x86 < 0x19 && !cpu_smt_possible()) {
          setup_force_cpu_cap(X86_FEATURE_SRSO_NO);
          srso_mitigation = SRSO_MITIGATION_NONE;
          return;
  }

and, in particular, sets srso_mitigation to NONE. This leads to
reporting

  Speculative Return Stack Overflow: Vulnerable

on Zen2 machines.

There's a far bigger confusion with what SRSO_NO means and how it is
used in the code but this will be a matter of future fixes and
restructuring to how the SRSO mitigation gets determined.

Fix the reporting issue for now.

Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: David Kaplan <david.kaplan@amd.com>
Link: https://lore.kernel.org/20250513110405.15872-1-bp@kernel.org
This commit is contained in:
Borislav Petkov (AMD) 2025-05-13 13:04:05 +02:00
parent c4070e1996
commit 891d3b8be3
1 changed files with 3 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
arch/x86/kernel/cpu/bugs.c
View File

@ -2942,7 +2942,9 @@ static void __init srso_update_mitigation(void)
boot_cpu_has(X86_FEATURE_IBPB_BRTYPE))
srso_mitigation = SRSO_MITIGATION_IBPB;
if (boot_cpu_has_bug(X86_BUG_SRSO) && !cpu_mitigations_off())
if (boot_cpu_has_bug(X86_BUG_SRSO) &&
!cpu_mitigations_off() &&
!boot_cpu_has(X86_FEATURE_SRSO_NO))
pr_info("%s\n", srso_strings[srso_mitigation]);
}