Commit 805b743f authored by Borislav Petkov (AMD)'s avatar Borislav Petkov (AMD) Committed by Ingo Molnar
Browse files

x86/microcode/AMD: Extend the SHA check to Zen5, block loading of any... 


x86/microcode/AMD: Extend the SHA check to Zen5, block loading of any unreleased standalone Zen5 microcode patches

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: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: default avatarIngo 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
parent 164a9f71

arch/x86/kernel/cpu/microcode/amd.c

+7 −2
Original line number Diff line number Diff line
@@ -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 patch_id, u32 cur_rev, const u8 *data, unsi 
	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))