diff --git a/arch/powerpc/kvm/book3s_hv_uvmem.c b/arch/powerpc/kvm/book3s_hv_uvmem.c
index 709ebd578394..e2d6f9327f77 100644
--- a/arch/powerpc/kvm/book3s_hv_uvmem.c
+++ b/arch/powerpc/kvm/book3s_hv_uvmem.c
@@ -410,6 +410,7 @@ static int kvmppc_memslot_page_merge(struct kvm *kvm,
 			ret = H_STATE;
 			break;
 		}
+		vma_start_write(vma);
 		/* Copy vm_flags to avoid partial modifications in ksm_madvise */
 		vm_flags = vma->vm_flags;
 		ret = ksm_madvise(vma, vma->vm_start, vma->vm_end,
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index 9854d44ae18e..70bd2951b68d 100644
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -667,6 +667,7 @@ static void userfaultfd_event_wait_completion(struct userfaultfd_ctx *ctx,
 		mmap_write_lock(mm);
 		for_each_vma(vmi, vma) {
 			if (vma->vm_userfaultfd_ctx.ctx == release_new_ctx) {
+				vma_start_write(vma);
 				vma->vm_userfaultfd_ctx = NULL_VM_UFFD_CTX;
 				userfaultfd_set_vm_flags(vma,
 							 vma->vm_flags & ~__VM_UFFD_FLAGS);
@@ -702,6 +703,7 @@ int dup_userfaultfd(struct vm_area_struct *vma, struct list_head *fcs)
 
 	octx = vma->vm_userfaultfd_ctx.ctx;
 	if (!octx || !(octx->features & UFFD_FEATURE_EVENT_FORK)) {
+		vma_start_write(vma);
 		vma->vm_userfaultfd_ctx = NULL_VM_UFFD_CTX;
 		userfaultfd_set_vm_flags(vma, vma->vm_flags & ~__VM_UFFD_FLAGS);
 		return 0;
@@ -783,6 +785,7 @@ void mremap_userfaultfd_prep(struct vm_area_struct *vma,
 		atomic_inc(&ctx->mmap_changing);
 	} else {
 		/* Drop uffd context if remap feature not enabled */
+		vma_start_write(vma);
 		vma->vm_userfaultfd_ctx = NULL_VM_UFFD_CTX;
 		userfaultfd_set_vm_flags(vma, vma->vm_flags & ~__VM_UFFD_FLAGS);
 	}
@@ -940,6 +943,7 @@ static int userfaultfd_release(struct inode *inode, struct file *file)
 			prev = vma;
 		}
 
+		vma_start_write(vma);
 		userfaultfd_set_vm_flags(vma, new_flags);
 		vma->vm_userfaultfd_ctx = NULL_VM_UFFD_CTX;
 	}
@@ -1511,6 +1515,7 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx,
 		 * the next vma was merged into the current one and
 		 * the current one has not been updated yet.
 		 */
+		vma_start_write(vma);
 		userfaultfd_set_vm_flags(vma, new_flags);
 		vma->vm_userfaultfd_ctx.ctx = ctx;
 
@@ -1694,6 +1699,7 @@ static int userfaultfd_unregister(struct userfaultfd_ctx *ctx,
 		 * the next vma was merged into the current one and
 		 * the current one has not been updated yet.
 		 */
+		vma_start_write(vma);
 		userfaultfd_set_vm_flags(vma, new_flags);
 		vma->vm_userfaultfd_ctx = NULL_VM_UFFD_CTX;
 
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 49eafc62b4e6..5a6ff9140090 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -774,18 +774,22 @@ static inline void vm_flags_init(struct vm_area_struct *vma,
 	ACCESS_PRIVATE(vma, __vm_flags) = flags;
 }
 
-/* Use when VMA is part of the VMA tree and modifications need coordination */
+/*
+ * Use when VMA is part of the VMA tree and modifications need coordination
+ * Note: vm_flags_reset and vm_flags_reset_once do not lock the vma and
+ * it should be locked explicitly beforehand.
+ */
 static inline void vm_flags_reset(struct vm_area_struct *vma,
 				  vm_flags_t flags)
 {
-	vma_start_write(vma);
+	vma_assert_write_locked(vma);
 	vm_flags_init(vma, flags);
 }
 
 static inline void vm_flags_reset_once(struct vm_area_struct *vma,
 				       vm_flags_t flags)
 {
-	vma_start_write(vma);
+	vma_assert_write_locked(vma);
 	WRITE_ONCE(ACCESS_PRIVATE(vma, __vm_flags), flags);
 }
 
diff --git a/mm/madvise.c b/mm/madvise.c
index da65f8bd9ac3..8498f700c284 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -173,9 +173,8 @@ static int madvise_update_vma(struct vm_area_struct *vma,
 	}
 
 success:
-	/*
-	 * vm_flags is protected by the mmap_lock held in write mode.
-	 */
+	/* vm_flags is protected by the mmap_lock held in write mode. */
+	vma_start_write(vma);
 	vm_flags_reset(vma, new_flags);
 	if (!vma->vm_file || vma_is_anon_shmem(vma)) {
 		error = replace_anon_vma_name(vma, anon_name);
diff --git a/mm/mlock.c b/mm/mlock.c
index 0a0c996c5c21..1746600a2e14 100644
--- a/mm/mlock.c
+++ b/mm/mlock.c
@@ -386,6 +386,7 @@ static void mlock_vma_pages_range(struct vm_area_struct *vma,
 	 */
 	if (newflags & VM_LOCKED)
 		newflags |= VM_IO;
+	vma_start_write(vma);
 	vm_flags_reset_once(vma, newflags);
 
 	lru_add_drain();
@@ -460,9 +461,9 @@ success:
 	 * It's okay if try_to_unmap_one unmaps a page just after we
 	 * set VM_LOCKED, populate_vma_page_range will bring it back.
 	 */
-
 	if ((newflags & VM_LOCKED) && (oldflags & VM_LOCKED)) {
 		/* No work to do, and mlocking twice would be wrong */
+		vma_start_write(vma);
 		vm_flags_reset(vma, newflags);
 	} else {
 		mlock_vma_pages_range(vma, start, end, newflags);
diff --git a/mm/mprotect.c b/mm/mprotect.c
index 3f36c88a238e..7cd7f644da80 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -656,6 +656,7 @@ success:
 	 * vm_flags and vm_page_prot are protected by the mmap_lock
 	 * held in write mode.
 	 */
+	vma_start_write(vma);
 	vm_flags_reset(vma, newflags);
 	if (vma_wants_manual_pte_write_upgrade(vma))
 		mm_cp_flags |= MM_CP_TRY_CHANGE_WRITABLE;