diff --git a/mm/mmap.c b/mm/mmap.c
index 9ed3a06242a0e59e4c3f66be2485921e214eaea9..2b7d9e78a5693982a70f2b7f61d42afcad20ef01 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2069,6 +2069,18 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address)
 		if (vma->vm_pgoff + (size >> PAGE_SHIFT) >= vma->vm_pgoff) {
 			error = acct_stack_growth(vma, size, grow);
 			if (!error) {
+				/*
+				 * vma_gap_update() doesn't support concurrent
+				 * updates, but we only hold a shared mmap_sem
+				 * lock here, so we need to protect against
+				 * concurrent vma expansions.
+				 * vma_lock_anon_vma() doesn't help here, as
+				 * we don't guarantee that all growable vmas
+				 * in a mm share the same root anon vma.
+				 * So, we reuse mm->page_table_lock to guard
+				 * against concurrent vma expansions.
+				 */
+				spin_lock(&vma->vm_mm->page_table_lock);
 				anon_vma_interval_tree_pre_update_vma(vma);
 				vma->vm_end = address;
 				anon_vma_interval_tree_post_update_vma(vma);
@@ -2076,6 +2088,8 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address)
 					vma_gap_update(vma->vm_next);
 				else
 					vma->vm_mm->highest_vm_end = address;
+				spin_unlock(&vma->vm_mm->page_table_lock);
+
 				perf_event_mmap(vma);
 			}
 		}
@@ -2126,11 +2140,25 @@ int expand_downwards(struct vm_area_struct *vma,
 		if (grow <= vma->vm_pgoff) {
 			error = acct_stack_growth(vma, size, grow);
 			if (!error) {
+				/*
+				 * vma_gap_update() doesn't support concurrent
+				 * updates, but we only hold a shared mmap_sem
+				 * lock here, so we need to protect against
+				 * concurrent vma expansions.
+				 * vma_lock_anon_vma() doesn't help here, as
+				 * we don't guarantee that all growable vmas
+				 * in a mm share the same root anon vma.
+				 * So, we reuse mm->page_table_lock to guard
+				 * against concurrent vma expansions.
+				 */
+				spin_lock(&vma->vm_mm->page_table_lock);
 				anon_vma_interval_tree_pre_update_vma(vma);
 				vma->vm_start = address;
 				vma->vm_pgoff -= grow;
 				anon_vma_interval_tree_post_update_vma(vma);
 				vma_gap_update(vma);
+				spin_unlock(&vma->vm_mm->page_table_lock);
+
 				perf_event_mmap(vma);
 			}
 		}