Merge tag 'mm-hotfixes-stable-2023-04-07-16-23' of...

Merge tag 'mm-hotfixes-stable-2023-04-07-16-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM fixes from Andrew Morton:
 "28 hotfixes.

  23 are cc:stable and the other five address issues which were
  introduced during this merge cycle.

  20 are for MM and the remainder are for other subsystems"

* tag 'mm-hotfixes-stable-2023-04-07-16-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (28 commits)
  maple_tree: fix a potential concurrency bug in RCU mode
  maple_tree: fix get wrong data_end in mtree_lookup_walk()
  mm/swap: fix swap_info_struct race between swapoff and get_swap_pages()
  nilfs2: fix sysfs interface lifetime
  mm: take a page reference when removing device exclusive entries
  mm: vmalloc: avoid warn_alloc noise caused by fatal signal
  nilfs2: initialize "struct nilfs_binfo_dat"->bi_pad field
  nilfs2: fix potential UAF of struct nilfs_sc_info in nilfs_segctor_thread()
  zsmalloc: document freeable stats
  zsmalloc: document new fullness grouping
  fsdax: force clear dirty mark if CoW
  mm/hugetlb: fix uffd wr-protection for CoW optimization path
  mm: enable maple tree RCU mode by default
  maple_tree: add RCU lock checking to rcu callback functions
  maple_tree: add smp_rmb() to dead node detection
  maple_tree: fix write memory barrier of nodes once dead for RCU mode
  maple_tree: remove extra smp_wmb() from mas_dead_leaves()
  maple_tree: fix freeing of nodes in rcu mode
  maple_tree: detect dead nodes in mas_start()
  maple_tree: be more cautious about dead nodes
  ...

.mailmap

@@ -265,7 +265,9 @@ Krzysztof Kozlowski <krzk@kernel.org> <k.kozlowski@samsung.com>
 Krzysztof Kozlowski <krzk@kernel.org> <krzysztof.kozlowski@canonical.com>
 Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
 Kuogee Hsieh <quic_khsieh@quicinc.com> <khsieh@codeaurora.org>
+Leonard Crestez <leonard.crestez@nxp.com> Leonard Crestez <cdleonard@gmail.com>
 Leonardo Bras <leobras.c@gmail.com> <leonardo@linux.ibm.com>
+Leonard Göhrs <l.goehrs@pengutronix.de>
 Leonid I Ananiev <leonid.i.ananiev@intel.com>
 Leon Romanovsky <leon@kernel.org> <leon@leon.nu>
 Leon Romanovsky <leon@kernel.org> <leonro@mellanox.com>

fs/dax.c

@@ -781,6 +781,33 @@ static int __dax_invalidate_entry(struct address_space *mapping,
 	return ret;
 }
 
+static int __dax_clear_dirty_range(struct address_space *mapping,
+		pgoff_t start, pgoff_t end)
+{
+	XA_STATE(xas, &mapping->i_pages, start);
+	unsigned int scanned = 0;
+	void *entry;
+
+	xas_lock_irq(&xas);
+	xas_for_each(&xas, entry, end) {
+		entry = get_unlocked_entry(&xas, 0);
+		xas_clear_mark(&xas, PAGECACHE_TAG_DIRTY);
+		xas_clear_mark(&xas, PAGECACHE_TAG_TOWRITE);
+		put_unlocked_entry(&xas, entry, WAKE_NEXT);
+
+		if (++scanned % XA_CHECK_SCHED)
+			continue;
+
+		xas_pause(&xas);
+		xas_unlock_irq(&xas);
+		cond_resched();
+		xas_lock_irq(&xas);
+	}
+	xas_unlock_irq(&xas);
+
+	return 0;
+}
+
 /*
  * Delete DAX entry at @index from @mapping.  Wait for it
  * to be unlocked before deleting it.
@@ -1258,15 +1285,20 @@ static s64 dax_unshare_iter(struct iomap_iter *iter)
 	/* don't bother with blocks that are not shared to start with */
 	if (!(iomap->flags & IOMAP_F_SHARED))
 		return length;
-	/* don't bother with holes or unwritten extents */
-	if (srcmap->type == IOMAP_HOLE || srcmap->type == IOMAP_UNWRITTEN)
-		return length;
 
 	id = dax_read_lock();
 	ret = dax_iomap_direct_access(iomap, pos, length, &daddr, NULL);
 	if (ret < 0)
 		goto out_unlock;
 
+	/* zero the distance if srcmap is HOLE or UNWRITTEN */
+	if (srcmap->flags & IOMAP_F_SHARED || srcmap->type == IOMAP_UNWRITTEN) {
+		memset(daddr, 0, length);
+		dax_flush(iomap->dax_dev, daddr, length);
+		ret = length;
+		goto out_unlock;
+	}
+
 	ret = dax_iomap_direct_access(srcmap, pos, length, &saddr, NULL);
 	if (ret < 0)
 		goto out_unlock;
@@ -1435,6 +1467,16 @@ static loff_t dax_iomap_iter(const struct iomap_iter *iomi,
 	 * written by write(2) is visible in mmap.
 	 */
 	if (iomap->flags & IOMAP_F_NEW || cow) {
+		/*
+		 * Filesystem allows CoW on non-shared extents. The src extents
+		 * may have been mmapped with dirty mark before. To be able to
+		 * invalidate its dax entries, we need to clear the dirty mark
+		 * in advance.
+		 */
+		if (cow)
+			__dax_clear_dirty_range(iomi->inode->i_mapping,
+						pos >> PAGE_SHIFT,
+						(end - 1) >> PAGE_SHIFT);
 		invalidate_inode_pages2_range(iomi->inode->i_mapping,
 					      pos >> PAGE_SHIFT,
 					      (end - 1) >> PAGE_SHIFT);
@@ -2022,8 +2064,8 @@ int dax_dedupe_file_range_compare(struct inode *src, loff_t srcoff,
 
 	while ((ret = iomap_iter(&src_iter, ops)) > 0 &&
 	       (ret = iomap_iter(&dst_iter, ops)) > 0) {
-		compared = dax_range_compare_iter(&src_iter, &dst_iter, len,
-						  same);
+		compared = dax_range_compare_iter(&src_iter, &dst_iter,
+				min(src_iter.len, dst_iter.len), same);
 		if (compared < 0)
 			return ret;
 		src_iter.processed = dst_iter.processed = compared;

fs/nilfs2/btree.c

@@ -2219,6 +2219,7 @@ static int nilfs_btree_assign_p(struct nilfs_bmap *btree,
 	/* on-disk format */
 	binfo->bi_dat.bi_blkoff = cpu_to_le64(key);
 	binfo->bi_dat.bi_level = level;
+	memset(binfo->bi_dat.bi_pad, 0, sizeof(binfo->bi_dat.bi_pad));
 
 	return 0;
 }

fs/nilfs2/direct.c

@@ -314,6 +314,7 @@ static int nilfs_direct_assign_p(struct nilfs_bmap *direct,
 
 	binfo->bi_dat.bi_blkoff = cpu_to_le64(key);
 	binfo->bi_dat.bi_level = 0;
+	memset(binfo->bi_dat.bi_pad, 0, sizeof(binfo->bi_dat.bi_pad));
 
 	return 0;
 }

fs/nilfs2/segment.c

@@ -2609,11 +2609,10 @@ static int nilfs_segctor_thread(void *arg)
 	goto loop;
 
  end_thread:
-	spin_unlock(&sci->sc_state_lock);
-
 	/* end sync. */
 	sci->sc_task = NULL;
 	wake_up(&sci->sc_wait_task); /* for nilfs_segctor_kill_thread() */
+	spin_unlock(&sci->sc_state_lock);
 	return 0;
 }
 

fs/nilfs2/super.c

@@ -482,6 +482,7 @@ static void nilfs_put_super(struct super_block *sb)
 		up_write(&nilfs->ns_sem);
 	}
 
+	nilfs_sysfs_delete_device_group(nilfs);
 	iput(nilfs->ns_sufile);
 	iput(nilfs->ns_cpfile);
 	iput(nilfs->ns_dat);
@@ -1105,6 +1106,7 @@ nilfs_fill_super(struct super_block *sb, void *data, int silent)
 	nilfs_put_root(fsroot);
 
  failed_unload:
+	nilfs_sysfs_delete_device_group(nilfs);
 	iput(nilfs->ns_sufile);
 	iput(nilfs->ns_cpfile);
 	iput(nilfs->ns_dat);

fs/nilfs2/the_nilfs.c

@@ -87,7 +87,6 @@ void destroy_nilfs(struct the_nilfs *nilfs)
 {
 	might_sleep();
 	if (nilfs_init(nilfs)) {
-		nilfs_sysfs_delete_device_group(nilfs);
 		brelse(nilfs->ns_sbh[0]);
 		brelse(nilfs->ns_sbh[1]);
 	}
@@ -305,6 +304,10 @@ int load_nilfs(struct the_nilfs *nilfs, struct super_block *sb)
 		goto failed;
 	}
 
+	err = nilfs_sysfs_create_device_group(sb);
+	if (unlikely(err))
+		goto sysfs_error;
+
 	if (valid_fs)
 		goto skip_recovery;
 
@@ -366,6 +369,9 @@ int load_nilfs(struct the_nilfs *nilfs, struct super_block *sb)
 	goto failed;
 
  failed_unload:
+	nilfs_sysfs_delete_device_group(nilfs);
+
+ sysfs_error:
 	iput(nilfs->ns_cpfile);
 	iput(nilfs->ns_sufile);
 	iput(nilfs->ns_dat);
@@ -697,10 +703,6 @@ int init_nilfs(struct the_nilfs *nilfs, struct super_block *sb, char *data)
 	if (err)
 		goto failed_sbh;
 
-	err = nilfs_sysfs_create_device_group(sb);
-	if (err)
-		goto failed_sbh;
-
 	set_nilfs_init(nilfs);
 	err = 0;
  out:

include/linux/mm_types.h

@@ -774,7 +774,8 @@ struct mm_struct {
 	unsigned long cpu_bitmap[];
 };
 
-#define MM_MT_FLAGS	(MT_FLAGS_ALLOC_RANGE | MT_FLAGS_LOCK_EXTERN)
+#define MM_MT_FLAGS	(MT_FLAGS_ALLOC_RANGE | MT_FLAGS_LOCK_EXTERN | \
+			 MT_FLAGS_USE_RCU)
 extern struct mm_struct init_mm;
 
 /* Pointer magic because the dynamic array size confuses some compilers. */

kernel/fork.c

@@ -617,6 +617,7 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm,
 	if (retval)
 		goto out;
 
+	mt_clear_in_rcu(vmi.mas.tree);
 	for_each_vma(old_vmi, mpnt) {
 		struct file *file;
 
@@ -700,6 +701,8 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm,
 	retval = arch_dup_mmap(oldmm, mm);
 loop_out:
 	vma_iter_free(&vmi);
+	if (!retval)
+		mt_set_in_rcu(vmi.mas.tree);
 out:
 	mmap_write_unlock(mm);
 	flush_tlb_mm(oldmm);

lib/Kconfig.debug

@@ -1143,7 +1143,7 @@ menu "Scheduler Debugging"
 
 config SCHED_DEBUG
 	bool "Collect scheduler debugging info"
-	depends on DEBUG_KERNEL && PROC_FS
+	depends on DEBUG_KERNEL && DEBUG_FS
 	default y
 	help
 	  If you say Y here, the /sys/kernel/debug/sched file will be provided
@@ -1392,7 +1392,7 @@ config LOCKDEP_STACK_TRACE_HASH_BITS
 	range 10 30
 	default 14
 	help
-	  Try increasing this value if you need large MAX_STACK_TRACE_ENTRIES.
+	  Try increasing this value if you need large STACK_TRACE_HASH_SIZE.
 
 config LOCKDEP_CIRCULAR_QUEUE_BITS
 	int "Bitsize for elements in circular_queue struct"

mm/hugetlb.c

@@ -5478,7 +5478,7 @@ static vm_fault_t hugetlb_wp(struct mm_struct *mm, struct vm_area_struct *vma,
 		       struct folio *pagecache_folio, spinlock_t *ptl)
 {
 	const bool unshare = flags & FAULT_FLAG_UNSHARE;
-	pte_t pte;
+	pte_t pte = huge_ptep_get(ptep);
 	struct hstate *h = hstate_vma(vma);
 	struct page *old_page;
 	struct folio *new_folio;
@@ -5487,6 +5487,17 @@ static vm_fault_t hugetlb_wp(struct mm_struct *mm, struct vm_area_struct *vma,
 	unsigned long haddr = address & huge_page_mask(h);
 	struct mmu_notifier_range range;
 
+	/*
+	 * Never handle CoW for uffd-wp protected pages.  It should be only
+	 * handled when the uffd-wp protection is removed.
+	 *
+	 * Note that only the CoW optimization path (in hugetlb_no_page())
+	 * can trigger this, because hugetlb_fault() will always resolve
+	 * uffd-wp bit first.
+	 */
+	if (!unshare && huge_pte_uffd_wp(pte))
+		return 0;
+
 	/*
 	 * hugetlb does not support FOLL_FORCE-style write faults that keep the
 	 * PTE mapped R/O such as maybe_mkwrite() would do.
@@ -5500,7 +5511,6 @@ static vm_fault_t hugetlb_wp(struct mm_struct *mm, struct vm_area_struct *vma,
 		return 0;
 	}
 
-	pte = huge_ptep_get(ptep);
 	old_page = pte_page(pte);
 
 	delayacct_wpcopy_start();

mm/kfence/core.c

@@ -556,15 +556,11 @@ static unsigned long kfence_init_pool(void)
 	 * enters __slab_free() slow-path.
 	 */
 	for (i = 0; i < KFENCE_POOL_SIZE / PAGE_SIZE; i++) {
-		struct slab *slab = page_slab(&pages[i]);
+		struct slab *slab = page_slab(nth_page(pages, i));
 
 		if (!i || (i % 2))
 			continue;
 
-		/* Verify we do not have a compound head page. */
-		if (WARN_ON(compound_head(&pages[i]) != &pages[i]))
-			return addr;
-
 		__folio_set_slab(slab_folio(slab));
 #ifdef CONFIG_MEMCG
 		slab->memcg_data = (unsigned long)&kfence_metadata[i / 2 - 1].objcg |
@@ -597,12 +593,26 @@ static unsigned long kfence_init_pool(void)
 
 		/* Protect the right redzone. */
 		if (unlikely(!kfence_protect(addr + PAGE_SIZE)))
-			return addr;
+			goto reset_slab;
 
 		addr += 2 * PAGE_SIZE;
 	}
 
 	return 0;
+
+reset_slab:
+	for (i = 0; i < KFENCE_POOL_SIZE / PAGE_SIZE; i++) {
+		struct slab *slab = page_slab(nth_page(pages, i));
+
+		if (!i || (i % 2))
+			continue;
+#ifdef CONFIG_MEMCG
+		slab->memcg_data = 0;
+#endif
+		__folio_clear_slab(slab_folio(slab));
+	}
+
+	return addr;
 }
 
 static bool __init kfence_init_pool_early(void)
@@ -632,16 +642,6 @@ static bool __init kfence_init_pool_early(void)
 	 * fails for the first page, and therefore expect addr==__kfence_pool in
 	 * most failure cases.
 	 */
-	for (char *p = (char *)addr; p < __kfence_pool + KFENCE_POOL_SIZE; p += PAGE_SIZE) {
-		struct slab *slab = virt_to_slab(p);
-
-		if (!slab)
-			continue;
-#ifdef CONFIG_MEMCG
-		slab->memcg_data = 0;
-#endif
-		__folio_clear_slab(slab_folio(slab));
-	}
 	memblock_free_late(__pa(addr), KFENCE_POOL_SIZE - (addr - (unsigned long)__kfence_pool));
 	__kfence_pool = NULL;
 	return false;

mm/memory.c

@@ -3563,8 +3563,21 @@ static vm_fault_t remove_device_exclusive_entry(struct vm_fault *vmf)
 	struct vm_area_struct *vma = vmf->vma;
 	struct mmu_notifier_range range;
 
-	if (!folio_lock_or_retry(folio, vma->vm_mm, vmf->flags))
+	/*
+	 * We need a reference to lock the folio because we don't hold
+	 * the PTL so a racing thread can remove the device-exclusive
+	 * entry and unmap it. If the folio is free the entry must
+	 * have been removed already. If it happens to have already
+	 * been re-allocated after being freed all we do is lock and
+	 * unlock it.
+	 */
+	if (!folio_try_get(folio))
+		return 0;
+
+	if (!folio_lock_or_retry(folio, vma->vm_mm, vmf->flags)) {
+		folio_put(folio);
 		return VM_FAULT_RETRY;
+	}
 	mmu_notifier_range_init_owner(&range, MMU_NOTIFY_EXCLUSIVE, 0,
 				vma->vm_mm, vmf->address & PAGE_MASK,
 				(vmf->address & PAGE_MASK) + PAGE_SIZE, NULL);
@@ -3577,6 +3590,7 @@ static vm_fault_t remove_device_exclusive_entry(struct vm_fault *vmf)
 
 	pte_unmap_unlock(vmf->pte, vmf->ptl);
 	folio_unlock(folio);
+	folio_put(folio);
 
 	mmu_notifier_invalidate_range_end(&range);
 	return 0;

mm/mmap.c

@@ -2277,7 +2277,7 @@ do_vmi_align_munmap(struct vma_iterator *vmi, struct vm_area_struct *vma,
 	int count = 0;
 	int error = -ENOMEM;
 	MA_STATE(mas_detach, &mt_detach, 0, 0);
-	mt_init_flags(&mt_detach, MT_FLAGS_LOCK_EXTERN);
+	mt_init_flags(&mt_detach, vmi->mas.tree->ma_flags & MT_FLAGS_LOCK_MASK);
 	mt_set_external_lock(&mt_detach, &mm->mmap_lock);
 
 	/*
@@ -3037,6 +3037,7 @@ void exit_mmap(struct mm_struct *mm)
 	 */
 	set_bit(MMF_OOM_SKIP, &mm->flags);
 	mmap_write_lock(mm);
+	mt_clear_in_rcu(&mm->mm_mt);
 	free_pgtables(&tlb, &mm->mm_mt, vma, FIRST_USER_ADDRESS,
 		      USER_PGTABLES_CEILING);
 	tlb_finish_mmu(&tlb);

mm/swapfile.c

@@ -679,6 +679,7 @@ static void __del_from_avail_list(struct swap_info_struct *p)
 {
 	int nid;
 
+	assert_spin_locked(&p->lock);
 	for_each_node(nid)
 		plist_del(&p->avail_lists[nid], &swap_avail_heads[nid]);
 }
@@ -2434,8 +2435,8 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile)
 		spin_unlock(&swap_lock);
 		goto out_dput;
 	}
-	del_from_avail_list(p);
 	spin_lock(&p->lock);
+	del_from_avail_list(p);
 	if (p->prio < 0) {
 		struct swap_info_struct *si = p;
 		int nid;

mm/vmalloc.c

@@ -3042,9 +3042,11 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
 	 * allocation request, free them via vfree() if any.
 	 */
 	if (area->nr_pages != nr_small_pages) {
-		warn_alloc(gfp_mask, NULL,
-			"vmalloc error: size %lu, page order %u, failed to allocate pages",
-			area->nr_pages * PAGE_SIZE, page_order);
+		/* vm_area_alloc_pages() can also fail due to a fatal signal */
+		if (!fatal_signal_pending(current))
+			warn_alloc(gfp_mask, NULL,
+				"vmalloc error: size %lu, page order %u, failed to allocate pages",
+				area->nr_pages * PAGE_SIZE, page_order);
 		goto fail;
 	}
 

tools/testing/radix-tree/maple.c

@@ -108,6 +108,7 @@ static noinline void check_new_node(struct maple_tree *mt)
 	MT_BUG_ON(mt, mn->slot[1] != NULL);
 	MT_BUG_ON(mt, mas_allocated(&mas) != 0);
 
+	mn->parent = ma_parent_ptr(mn);
 	ma_free_rcu(mn);
 	mas.node = MAS_START;
 	mas_nomem(&mas, GFP_KERNEL);
@@ -160,6 +161,7 @@ static noinline void check_new_node(struct maple_tree *mt)
 		MT_BUG_ON(mt, mas_allocated(&mas) != i);
 		MT_BUG_ON(mt, !mn);
 		MT_BUG_ON(mt, not_empty(mn));
+		mn->parent = ma_parent_ptr(mn);
 		ma_free_rcu(mn);
 	}
 
@@ -192,6 +194,7 @@ static noinline void check_new_node(struct maple_tree *mt)
 		MT_BUG_ON(mt, not_empty(mn));
 		MT_BUG_ON(mt, mas_allocated(&mas) != i - 1);
 		MT_BUG_ON(mt, !mn);
+		mn->parent = ma_parent_ptr(mn);
 		ma_free_rcu(mn);
 	}
 
@@ -210,6 +213,7 @@ static noinline void check_new_node(struct maple_tree *mt)
 			mn = mas_pop_node(&mas);
 			MT_BUG_ON(mt, not_empty(mn));
 			MT_BUG_ON(mt, mas_allocated(&mas) != j - 1);
+			mn->parent = ma_parent_ptr(mn);
 			ma_free_rcu(mn);
 		}
 		MT_BUG_ON(mt, mas_allocated(&mas) != 0);
@@ -233,6 +237,7 @@ static noinline void check_new_node(struct maple_tree *mt)
 			MT_BUG_ON(mt, mas_allocated(&mas) != i - j);
 			mn = mas_pop_node(&mas);
 			MT_BUG_ON(mt, not_empty(mn));
+			mn->parent = ma_parent_ptr(mn);
 			ma_free_rcu(mn);
 			MT_BUG_ON(mt, mas_allocated(&mas) != i - j - 1);
 		}
@@ -269,6 +274,7 @@ static noinline void check_new_node(struct maple_tree *mt)
 			mn = mas_pop_node(&mas); /* get the next node. */
 			MT_BUG_ON(mt, mn == NULL);
 			MT_BUG_ON(mt, not_empty(mn));
+			mn->parent = ma_parent_ptr(mn);
 			ma_free_rcu(mn);
 		}
 		MT_BUG_ON(mt, mas_allocated(&mas) != 0);
@@ -294,6 +300,7 @@ static noinline void check_new_node(struct maple_tree *mt)
 			mn = mas_pop_node(&mas2); /* get the next node. */
 			MT_BUG_ON(mt, mn == NULL);
 			MT_BUG_ON(mt, not_empty(mn));
+			mn->parent = ma_parent_ptr(mn);
 			ma_free_rcu(mn);
 		}
 		MT_BUG_ON(mt, mas_allocated(&mas2) != 0);
@@ -334,10 +341,12 @@ static noinline void check_new_node(struct maple_tree *mt)
 	MT_BUG_ON(mt, mas_allocated(&mas) != MAPLE_ALLOC_SLOTS + 2);
 	mn = mas_pop_node(&mas);
 	MT_BUG_ON(mt, not_empty(mn));
+	mn->parent = ma_parent_ptr(mn);
 	ma_free_rcu(mn);
 	for (i = 1; i <= MAPLE_ALLOC_SLOTS + 1; i++) {
 		mn = mas_pop_node(&mas);
 		MT_BUG_ON(mt, not_empty(mn));
+		mn->parent = ma_parent_ptr(mn);
 		ma_free_rcu(mn);
 	}
 	MT_BUG_ON(mt, mas_allocated(&mas) != 0);
@@ -375,6 +384,7 @@ static noinline void check_new_node(struct maple_tree *mt)
 		mas_node_count(&mas, i); /* Request */
 		mas_nomem(&mas, GFP_KERNEL); /* Fill request */
 		mn = mas_pop_node(&mas); /* get the next node. */
+		mn->parent = ma_parent_ptr(mn);
 		ma_free_rcu(mn);
 		mas_destroy(&mas);
 
@@ -382,10 +392,13 @@ static noinline void check_new_node(struct maple_tree *mt)
 		mas_node_count(&mas, i); /* Request */
 		mas_nomem(&mas, GFP_KERNEL); /* Fill request */
 		mn = mas_pop_node(&mas); /* get the next node. */
+		mn->parent = ma_parent_ptr(mn);
 		ma_free_rcu(mn);
 		mn = mas_pop_node(&mas); /* get the next node. */
+		mn->parent = ma_parent_ptr(mn);
 		ma_free_rcu(mn);
 		mn = mas_pop_node(&mas); /* get the next node. */
+		mn->parent = ma_parent_ptr(mn);
 		ma_free_rcu(mn);
 		mas_destroy(&mas);
 	}
@@ -35369,6 +35382,7 @@ static noinline void check_prealloc(struct maple_tree *mt)
 	MT_BUG_ON(mt, allocated != 1 + height * 3);
 	mn = mas_pop_node(&mas);
 	MT_BUG_ON(mt, mas_allocated(&mas) != allocated - 1);
+	mn->parent = ma_parent_ptr(mn);
 	ma_free_rcu(mn);
 	MT_BUG_ON(mt, mas_preallocate(&mas, GFP_KERNEL) != 0);
 	mas_destroy(&mas);
@@ -35386,6 +35400,7 @@ static noinline void check_prealloc(struct maple_tree *mt)
 	mas_destroy(&mas);
 	allocated = mas_allocated(&mas);
 	MT_BUG_ON(mt, allocated != 0);
+	mn->parent = ma_parent_ptr(mn);
 	ma_free_rcu(mn);
 
 	MT_BUG_ON(mt, mas_preallocate(&mas, GFP_KERNEL) != 0);
@@ -35756,6 +35771,7 @@ void farmer_tests(void)
 	tree.ma_root = mt_mk_node(node, maple_leaf_64);
 	mt_dump(&tree);
 
+	node->parent = ma_parent_ptr(node);
 	ma_free_rcu(node);
 
 	/* Check things that will make lockdep angry */