Merge tag 'mm-hotfixes-stable-2025-02-01-03-56' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull misc fixes from Andrew Morton:
 "21 hotfixes. 8 are cc:stable and the remainder address post-6.13
  issues. 13 are for MM and 8 are for non-MM.

  All are singletons, please see the changelogs for details"

* tag 'mm-hotfixes-stable-2025-02-01-03-56' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (21 commits)
  MAINTAINERS: include linux-mm for xarray maintenance
  revert "xarray: port tests to kunit"
  MAINTAINERS: add lib/test_xarray.c
  mailmap, MAINTAINERS, docs: update Carlos's email address
  mm/hugetlb: fix hugepage allocation for interleaved memory nodes
  mm: gup: fix infinite loop within __get_longterm_locked
  mm, swap: fix reclaim offset calculation error during allocation
  .mailmap: update email address for Christopher Obbard
  kfence: skip __GFP_THISNODE allocations on NUMA systems
  nilfs2: fix possible int overflows in nilfs_fiemap()
  mm: compaction: use the proper flag to determine watermarks
  kernel: be more careful about dup_mmap() failures and uprobe registering
  mm/fake-numa: handle cases with no SRAT info
  mm: kmemleak: fix upper boundary check for physical address objects
  mailmap: add an entry for Hamza Mahfooz
  MAINTAINERS: mailmap: update Yosry Ahmed's email address
  scripts/gdb: fix aarch64 userspace detection in get_current_task
  mm/vmscan: accumulate nr_demoted for accurate demotion statistics
  ocfs2: fix incorrect CPU endianness conversion causing mount failure
  mm/zsmalloc: add __maybe_unused attribute for is_first_zpdesc()
  ...

1 files changed, 14 insertions, 3 deletions

diff --git a/kernel/fork.c b/kernel/fork.c
index cba5ede2c639..735405a9c5f3 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -760,7 +760,8 @@ loop_out:
 		mt_set_in_rcu(vmi.mas.tree);
 		ksm_fork(mm, oldmm);
 		khugepaged_fork(mm, oldmm);
-	} else if (mpnt) {
+	} else {
+
 		/*
 		 * The entire maple tree has already been duplicated. If the
 		 * mmap duplication fails, mark the failure point with
@@ -768,8 +769,18 @@ loop_out:
 		 * stop releasing VMAs that have not been duplicated after this
 		 * point.
 		 */
-		mas_set_range(&vmi.mas, mpnt->vm_start, mpnt->vm_end - 1);
-		mas_store(&vmi.mas, XA_ZERO_ENTRY);
+		if (mpnt) {
+			mas_set_range(&vmi.mas, mpnt->vm_start, mpnt->vm_end - 1);
+			mas_store(&vmi.mas, XA_ZERO_ENTRY);
+			/* Avoid OOM iterating a broken tree */
+			set_bit(MMF_OOM_SKIP, &mm->flags);
+		}
+		/*
+		 * The mm_struct is going to exit, but the locks will be dropped
+		 * first.  Set the mm_struct as unstable is advisable as it is
+		 * not fully initialised.
+		 */
+		set_bit(MMF_UNSTABLE, &mm->flags);
 	}
 out:
 	mmap_write_unlock(mm);