6.12-stable review patch. If anyone has any objections, please let me know.
------------------
From: Borislav Petkov (AMD) bp@alien8.de
commit 805b743fc163f1abef7ce1bea8eca8dfab5b685b upstream.
All Zen5 machines out there should get BIOS updates which update to the correct microcode patches addressing the microcode signature issue. However, silly people carve out random microcode blobs from BIOS packages and think are doing other people a service this way...
Block loading of any unreleased standalone Zen5 microcode patches.
Signed-off-by: Borislav Petkov (AMD) bp@alien8.de Signed-off-by: Ingo Molnar mingo@kernel.org Cc: stable@kernel.org Cc: Andrew Cooper andrew.cooper3@citrix.com Cc: Boris Ostrovsky boris.ostrovsky@oracle.com Cc: Linus Torvalds torvalds@linux-foundation.org Cc: Maciej S. Szmigiero mail@maciej.szmigiero.name Cc: Nikolay Borisov nik.borisov@suse.com Cc: Tom Lendacky thomas.lendacky@amd.com Link: https://lore.kernel.org/r/20250410114222.32523-1-bp@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/kernel/cpu/microcode/amd.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
--- a/arch/x86/kernel/cpu/microcode/amd.c +++ b/arch/x86/kernel/cpu/microcode/amd.c @@ -199,6 +199,12 @@ static bool need_sha_check(u32 cur_rev) case 0xa70c0: return cur_rev <= 0xa70C009; break; case 0xaa001: return cur_rev <= 0xaa00116; break; case 0xaa002: return cur_rev <= 0xaa00218; break; + case 0xb0021: return cur_rev <= 0xb002146; break; + case 0xb1010: return cur_rev <= 0xb101046; break; + case 0xb2040: return cur_rev <= 0xb204031; break; + case 0xb4040: return cur_rev <= 0xb404031; break; + case 0xb6000: return cur_rev <= 0xb600031; break; + case 0xb7000: return cur_rev <= 0xb700031; break; default: break; }
@@ -214,8 +220,7 @@ static bool verify_sha256_digest(u32 pat struct sha256_state s; int i;
- if (x86_family(bsp_cpuid_1_eax) < 0x17 || - x86_family(bsp_cpuid_1_eax) > 0x19) + if (x86_family(bsp_cpuid_1_eax) < 0x17) return true;
if (!need_sha_check(cur_rev))