From a66b6b07d0d3d0f80092f122c732c63a901e9289 Mon Sep 17 00:00:00 2001 From: "Borislav Petkov (AMD)" Date: Thu, 10 Apr 2025 13:42:22 +0200 Subject: [PATCH] x86/microcode/AMD: Extend the SHA check to Zen5, block loading of any unreleased standalone Zen5 microcode patches 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) Signed-off-by: Ingo Molnar Cc: Cc: Andrew Cooper Cc: Boris Ostrovsky Cc: Linus Torvalds Cc: Maciej S. Szmigiero Cc: Nikolay Borisov Cc: Tom Lendacky Link: https://lore.kernel.org/r/20250410114222.32523-1-bp@kernel.org Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/cpu/microcode/amd.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c index 5cd735728fa0..093d3ca43c46 100644 --- 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 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))