diff --git a/arch/arm64/mm/mmap.c b/arch/arm64/mm/mmap.c index 75f343009b4b..92b2f5097a96 100644 --- a/arch/arm64/mm/mmap.c +++ b/arch/arm64/mm/mmap.c @@ -91,7 +91,11 @@ pgprot_t vm_get_page_prot(vm_flags_t vm_flags) /* Short circuit GCS to avoid bloating the table. */ if (system_supports_gcs() && (vm_flags & VM_SHADOW_STACK)) { - prot = gcs_page_prot; + /* Honour mprotect(PROT_NONE) on shadow stack mappings */ + if (vm_flags & VM_ACCESS_FLAGS) + prot = gcs_page_prot; + else + prot = pgprot_val(protection_map[VM_NONE]); } else { prot = pgprot_val(protection_map[vm_flags & (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]);