From: "Borislav Petkov (AMD)" bp@alien8.de
stable inclusion from stable-v6.6.7 commit 903a1a1949c6c56beec74a4c2e6f1a51848a7941 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I8SSQ4
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
--------------------------------
commit 9b8493dc43044376716d789d07699f17d538a7c4 upstream.
Commit in Fixes added an AMD-specific microcode callback. However, it didn't check the CPU vendor the kernel runs on explicitly.
The only reason the Zenbleed check in it didn't run on other x86 vendors hardware was pure coincidental luck:
if (!cpu_has_amd_erratum(c, amd_zenbleed)) return;
gives true on other vendors because they don't have those families and models.
However, with the removal of the cpu_has_amd_erratum() in
05f5f73936fa ("x86/CPU/AMD: Drop now unused CPU erratum checking function")
that coincidental condition is gone, leading to the zenbleed check getting executed on other vendors too.
Add the explicit vendor check for the whole callback as it should've been done in the first place.
Fixes: 522b1d69219d ("x86/cpu/amd: Add a Zenbleed fix") Cc: stable@kernel.org Signed-off-by: Borislav Petkov (AMD) bp@alien8.de Link: https://lore.kernel.org/r/20231201184226.16749-1-bp@alien8.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- arch/x86/kernel/cpu/amd.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index ece2b5b7b0fe..6e4f23f314ac 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -1315,6 +1315,9 @@ static void zenbleed_check_cpu(void *unused)
void amd_check_microcode(void) { + if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD) + return; + on_each_cpu(zenbleed_check_cpu, NULL, 1); }