diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index 451ba7cbd5ad..0973dd09f11a 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c

@@ -486,6 +486,14 @@ static void do_bad_area(unsigned long far, unsigned long esr,
 	}
 }
 
+static bool is_gcs_fault(unsigned long esr)
+{
+	if (!esr_is_data_abort(esr))
+		return false;
+
+	return ESR_ELx_ISS2(esr) & ESR_ELx_GCS;
+}
+
 static bool is_el0_instruction_abort(unsigned long esr)
 {
 	return ESR_ELx_EC(esr) == ESR_ELx_EC_IABT_LOW;

@@ -500,6 +508,25 @@ static bool is_write_abort(unsigned long esr)
 	return (esr & ESR_ELx_WNR) && !(esr & ESR_ELx_CM);
 }
 
+static bool is_invalid_gcs_access(struct vm_area_struct *vma, u64 esr)
+{
+	if (!system_supports_gcs())
+		return false;
+
+	if (unlikely(is_gcs_fault(esr))) {
+		/* GCS accesses must be performed on a GCS page */
+		if (!(vma->vm_flags & VM_SHADOW_STACK))
+			return true;
+		if (!(vma->vm_flags & VM_WRITE))
+			return true;

+	} else if (unlikely(vma->vm_flags & VM_SHADOW_STACK)) {
+		/* Only GCS operations can write to a GCS page */
+		return is_write_abort(esr);
+	}
+
+	return false;
+}
+
 static int __kprobes do_page_fault(unsigned long far, unsigned long esr,
 				   struct pt_regs *regs)
 {

@@ -535,6 +562,14 @@ static int __kprobes do_page_fault(unsigned long far, unsigned long esr,
 		/* It was exec fault */
 		vm_flags = VM_EXEC;
 		mm_flags |= FAULT_FLAG_INSTRUCTION;
+	} else if (is_gcs_fault(esr)) {
+		/*
+		 * The GCS permission on a page implies both read and
+		 * write so always handle any GCS fault as a write fault,
+		 * we need to trigger CoW even for GCS reads.
+		 */
+		vm_flags = VM_WRITE;
+		mm_flags |= FAULT_FLAG_WRITE;
 	} else if (is_write_abort(esr)) {
 		/* It was write fault */
 		vm_flags = VM_WRITE;

@@ -568,6 +603,13 @@ static int __kprobes do_page_fault(unsigned long far, unsigned long esr,
 	if (!vma)
 		goto lock_mmap;
 
+	if (is_invalid_gcs_access(vma, esr)) {
+		vma_end_read(vma);
+		fault = 0;
+		si_code = SEGV_ACCERR;
+		goto bad_area;
+	}
+
 	if (!(vma->vm_flags & vm_flags)) {
 		vma_end_read(vma);
 		fault = 0;