diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index ab7d700..602e3a5 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -1035,6 +1035,25 @@
 };
 
 #ifdef CONFIG_MEM_SOFT_DIRTY
+
+#define is_cow_mapping(flags) (((flags) & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE)
+
+static inline bool pte_is_pinned(struct vm_area_struct *vma, unsigned long addr, pte_t pte)
+{
+	struct page *page;
+
+	if (!pte_write(pte))
+		return false;
+	if (!is_cow_mapping(vma->vm_flags))
+		return false;
+	if (likely(!atomic_read(&vma->vm_mm->has_pinned)))
+		return false;
+	page = vm_normal_page(vma, addr, pte);
+	if (!page)
+		return false;
+	return page_maybe_dma_pinned(page);
+}
+
 static inline void clear_soft_dirty(struct vm_area_struct *vma,
 		unsigned long addr, pte_t *pte)
 {
@@ -1049,6 +1068,8 @@
 	if (pte_present(ptent)) {
 		pte_t old_pte;
 
+		if (pte_is_pinned(vma, addr, ptent))
+			return;
 		old_pte = ptep_modify_prot_start(vma, addr, pte);
 		ptent = pte_wrprotect(old_pte);
 		ptent = pte_clear_soft_dirty(ptent);