1 files changed, 58 insertions, 14 deletions

diff --git a/arch/x86/kernel/cpu/mce/apei.c b/arch/x86/kernel/cpu/mce/apei.c
index 7f582b4ca1ca..0a89947e47bc 100644
--- a/arch/x86/kernel/cpu/mce/apei.c
+++ b/arch/x86/kernel/cpu/mce/apei.c
@@ -68,9 +68,9 @@ EXPORT_SYMBOL_GPL(apei_mce_report_mem_error);
 int apei_smca_report_x86_error(struct cper_ia_proc_ctx *ctx_info, u64 lapic_id)
 {
 	const u64 *i_mce = ((const u64 *) (ctx_info + 1));
+	unsigned int cpu, num_regs;
 	bool apicid_found = false;
 	struct mce_hw_err err;
-	unsigned int cpu;
 	struct mce *m;
 
 	if (!boot_cpu_has(X86_FEATURE_SMCA))
@@ -89,16 +89,12 @@ int apei_smca_report_x86_error(struct cper_ia_proc_ctx *ctx_info, u64 lapic_id)
 		return -EINVAL;
 
 	/*
-	 * The register array size must be large enough to include all the
-	 * SMCA registers which need to be extracted.
-	 *
 	 * The number of registers in the register array is determined by
 	 * Register Array Size/8 as defined in UEFI spec v2.8, sec N.2.4.2.2.
-	 * The register layout is fixed and currently the raw data in the
-	 * register array includes 6 SMCA registers which the kernel can
-	 * extract.
+	 * Sanity-check registers array size.
 	 */
-	if (ctx_info->reg_arr_size < 48)
+	num_regs = ctx_info->reg_arr_size >> 3;
+	if (!num_regs)
 		return -EINVAL;
 
 	for_each_possible_cpu(cpu) {
@@ -117,12 +113,60 @@ int apei_smca_report_x86_error(struct cper_ia_proc_ctx *ctx_info, u64 lapic_id)
 	mce_prep_record_per_cpu(cpu, m);
 
 	m->bank = (ctx_info->msr_addr >> 4) & 0xFF;
-	m->status = *i_mce;
-	m->addr = *(i_mce + 1);
-	m->misc = *(i_mce + 2);
-	/* Skipping MCA_CONFIG */
-	m->ipid = *(i_mce + 4);
-	m->synd = *(i_mce + 5);
+
+	/*
+	 * The SMCA register layout is fixed and includes 16 registers.
+	 * The end of the array may be variable, but the beginning is known.
+	 * Cap the number of registers to expected max (15).
+	 */
+	if (num_regs > 15)
+		num_regs = 15;
+
+	switch (num_regs) {
+	/* MCA_SYND2 */
+	case 15:
+		err.vendor.amd.synd2 = *(i_mce + 14);
+		fallthrough;
+	/* MCA_SYND1 */
+	case 14:
+		err.vendor.amd.synd1 = *(i_mce + 13);
+		fallthrough;
+	/* MCA_MISC4 */
+	case 13:
+	/* MCA_MISC3 */
+	case 12:
+	/* MCA_MISC2 */
+	case 11:
+	/* MCA_MISC1 */
+	case 10:
+	/* MCA_DEADDR */
+	case 9:
+	/* MCA_DESTAT */
+	case 8:
+	/* reserved */
+	case 7:
+	/* MCA_SYND */
+	case 6:
+		m->synd = *(i_mce + 5);
+		fallthrough;
+	/* MCA_IPID */
+	case 5:
+		m->ipid = *(i_mce + 4);
+		fallthrough;
+	/* MCA_CONFIG */
+	case 4:
+	/* MCA_MISC0 */
+	case 3:
+		m->misc = *(i_mce + 2);
+		fallthrough;
+	/* MCA_ADDR */
+	case 2:
+		m->addr = *(i_mce + 1);
+		fallthrough;
+	/* MCA_STATUS */
+	case 1:
+		m->status = *i_mce;
+	}
 
 	mce_log(&err);