1 files changed, 72 insertions, 41 deletions

diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c
index a881bf4c2011..3821a985f4ff 100644
--- a/arch/x86/kernel/cpu/microcode/amd.c
+++ b/arch/x86/kernel/cpu/microcode/amd.c
@@ -186,50 +186,61 @@ static u32 cpuid_to_ucode_rev(unsigned int val)
 	return p.ucode_rev;
 }
 
+static u32 get_cutoff_revision(u32 rev)
+{
+	switch (rev >> 8) {
+	case 0x80012: return 0x8001277; break;
+	case 0x80082: return 0x800820f; break;
+	case 0x83010: return 0x830107c; break;
+	case 0x86001: return 0x860010e; break;
+	case 0x86081: return 0x8608108; break;
+	case 0x87010: return 0x8701034; break;
+	case 0x8a000: return 0x8a0000a; break;
+	case 0xa0010: return 0xa00107a; break;
+	case 0xa0011: return 0xa0011da; break;
+	case 0xa0012: return 0xa001243; break;
+	case 0xa0082: return 0xa00820e; break;
+	case 0xa1011: return 0xa101153; break;
+	case 0xa1012: return 0xa10124e; break;
+	case 0xa1081: return 0xa108109; break;
+	case 0xa2010: return 0xa20102f; break;
+	case 0xa2012: return 0xa201212; break;
+	case 0xa4041: return 0xa404109; break;
+	case 0xa5000: return 0xa500013; break;
+	case 0xa6012: return 0xa60120a; break;
+	case 0xa7041: return 0xa704109; break;
+	case 0xa7052: return 0xa705208; break;
+	case 0xa7080: return 0xa708009; break;
+	case 0xa70c0: return 0xa70C009; break;
+	case 0xaa001: return 0xaa00116; break;
+	case 0xaa002: return 0xaa00218; break;
+	case 0xb0021: return 0xb002146; break;
+	case 0xb0081: return 0xb008111; break;
+	case 0xb1010: return 0xb101046; break;
+	case 0xb2040: return 0xb204031; break;
+	case 0xb4040: return 0xb404031; break;
+	case 0xb4041: return 0xb404101; break;
+	case 0xb6000: return 0xb600031; break;
+	case 0xb6080: return 0xb608031; break;
+	case 0xb7000: return 0xb700031; break;
+	default: break;
+
+	}
+	return 0;
+}
+
 static bool need_sha_check(u32 cur_rev)
 {
+	u32 cutoff;
+
 	if (!cur_rev) {
 		cur_rev = cpuid_to_ucode_rev(bsp_cpuid_1_eax);
 		pr_info_once("No current revision, generating the lowest one: 0x%x\n", cur_rev);
 	}
 
-	switch (cur_rev >> 8) {
-	case 0x80012: return cur_rev <= 0x8001277; break;
-	case 0x80082: return cur_rev <= 0x800820f; break;
-	case 0x83010: return cur_rev <= 0x830107c; break;
-	case 0x86001: return cur_rev <= 0x860010e; break;
-	case 0x86081: return cur_rev <= 0x8608108; break;
-	case 0x87010: return cur_rev <= 0x8701034; break;
-	case 0x8a000: return cur_rev <= 0x8a0000a; break;
-	case 0xa0010: return cur_rev <= 0xa00107a; break;
-	case 0xa0011: return cur_rev <= 0xa0011da; break;
-	case 0xa0012: return cur_rev <= 0xa001243; break;
-	case 0xa0082: return cur_rev <= 0xa00820e; break;
-	case 0xa1011: return cur_rev <= 0xa101153; break;
-	case 0xa1012: return cur_rev <= 0xa10124e; break;
-	case 0xa1081: return cur_rev <= 0xa108109; break;
-	case 0xa2010: return cur_rev <= 0xa20102f; break;
-	case 0xa2012: return cur_rev <= 0xa201212; break;
-	case 0xa4041: return cur_rev <= 0xa404109; break;
-	case 0xa5000: return cur_rev <= 0xa500013; break;
-	case 0xa6012: return cur_rev <= 0xa60120a; break;
-	case 0xa7041: return cur_rev <= 0xa704109; break;
-	case 0xa7052: return cur_rev <= 0xa705208; break;
-	case 0xa7080: return cur_rev <= 0xa708009; break;
-	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 0xb0081: return cur_rev <= 0xb008111; break;
-	case 0xb1010: return cur_rev <= 0xb101046; break;
-	case 0xb2040: return cur_rev <= 0xb204031; break;
-	case 0xb4040: return cur_rev <= 0xb404031; break;
-	case 0xb4041: return cur_rev <= 0xb404101; break;
-	case 0xb6000: return cur_rev <= 0xb600031; break;
-	case 0xb6080: return cur_rev <= 0xb608031; break;
-	case 0xb7000: return cur_rev <= 0xb700031; break;
-	default: break;
-	}
+	cutoff = get_cutoff_revision(cur_rev);
+	if (cutoff)
+		return cur_rev <= cutoff;
 
 	pr_info("You should not be seeing this. Please send the following couple of lines to x86-<at>-kernel.org\n");
 	pr_info("CPUID(1).EAX: 0x%x, current revision: 0x%x\n", bsp_cpuid_1_eax, cur_rev);
@@ -494,6 +505,7 @@ static int verify_patch(const u8 *buf, size_t buf_size, u32 *patch_size)
 {
 	u8 family = x86_family(bsp_cpuid_1_eax);
 	struct microcode_header_amd *mc_hdr;
+	u32 cur_rev, cutoff, patch_rev;
 	u32 sh_psize;
 	u16 proc_id;
 	u8 patch_fam;
@@ -533,11 +545,32 @@ static int verify_patch(const u8 *buf, size_t buf_size, u32 *patch_size)
 	proc_id	= mc_hdr->processor_rev_id;
 	patch_fam = 0xf + (proc_id >> 12);
 
-	ucode_dbg("Patch-ID 0x%08x: family: 0x%x\n", mc_hdr->patch_id, patch_fam);
-
 	if (patch_fam != family)
 		return 1;
 
+	cur_rev = get_patch_level();
+
+	/* No cutoff revision means old/unaffected by signing algorithm weakness => matches */
+	cutoff = get_cutoff_revision(cur_rev);
+	if (!cutoff)
+		goto ok;
+
+	patch_rev = mc_hdr->patch_id;
+
+	ucode_dbg("cur_rev: 0x%x, cutoff: 0x%x, patch_rev: 0x%x\n",
+		  cur_rev, cutoff, patch_rev);
+
+	if (cur_rev <= cutoff && patch_rev <= cutoff)
+		goto ok;
+
+	if (cur_rev > cutoff && patch_rev > cutoff)
+		goto ok;
+
+	return 1;
+
+ok:
+	ucode_dbg("Patch-ID 0x%08x: family: 0x%x\n", mc_hdr->patch_id, patch_fam);
+
 	return 0;
 }
 
@@ -606,8 +639,6 @@ static size_t parse_container(u8 *ucode, size_t size, struct cont_desc *desc)
 
 		mc = (struct microcode_amd *)(buf + SECTION_HDR_SIZE);
 
-		ucode_dbg("patch_id: 0x%x\n", mc->hdr.patch_id);
-
 		if (mc_patch_matches(mc, eq_id)) {
 			desc->psize = patch_size;
 			desc->mc = mc;