Merge tag 'mm-hotfixes-stable-2025-04-16-19-59' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull misc hotfixes from Andrew Morton:
 "31 hotfixes.

  9 are cc:stable and the remainder address post-6.15 issues or aren't
  considered necessary for -stable kernels.

  22 patches are for MM, 9 are otherwise"

* tag 'mm-hotfixes-stable-2025-04-16-19-59' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (31 commits)
  MAINTAINERS: update HUGETLB reviewers
  mm: fix apply_to_existing_page_range()
  selftests/mm: fix compiler -Wmaybe-uninitialized warning
  alloc_tag: handle incomplete bulk allocations in vm_module_tags_populate
  mailmap: add entry for Jean-Michel Hautbois
  mm: (un)track_pfn_copy() fix + doc improvements
  mm: fix filemap_get_folios_contig returning batches of identical folios
  mm/hugetlb: add a line break at the end of the format string
  selftests: mincore: fix tmpfs mincore test failure
  mm/hugetlb: fix set_max_huge_pages() when there are surplus pages
  mm/cma: report base address of single range correctly
  mm: page_alloc: speed up fallbacks in rmqueue_bulk()
  kunit: slub: add module description
  mm/kasan: add module decription
  ucs2_string: add module description
  zlib: add module description
  fpga: tests: add module descriptions
  samples/livepatch: add module descriptions
  ASN.1: add module description
  mm/vma: add give_up_on_oom option on modify/merge, use in uffd release
  ...

1 files changed, 11 insertions, 2 deletions

diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
index fbf2cf62ab9f..7d5d709cc838 100644
--- a/mm/userfaultfd.c
+++ b/mm/userfaultfd.c
@@ -1902,6 +1902,14 @@ struct vm_area_struct *userfaultfd_clear_vma(struct vma_iterator *vmi,
 					     unsigned long end)
 {
 	struct vm_area_struct *ret;
+	bool give_up_on_oom = false;
+
+	/*
+	 * If we are modifying only and not splitting, just give up on the merge
+	 * if OOM prevents us from merging successfully.
+	 */
+	if (start == vma->vm_start && end == vma->vm_end)
+		give_up_on_oom = true;
 
 	/* Reset ptes for the whole vma range if wr-protected */
 	if (userfaultfd_wp(vma))
@@ -1909,7 +1917,7 @@ struct vm_area_struct *userfaultfd_clear_vma(struct vma_iterator *vmi,
 
 	ret = vma_modify_flags_uffd(vmi, prev, vma, start, end,
 				    vma->vm_flags & ~__VM_UFFD_FLAGS,
-				    NULL_VM_UFFD_CTX);
+				    NULL_VM_UFFD_CTX, give_up_on_oom);
 
 	/*
 	 * In the vma_merge() successful mprotect-like case 8:
@@ -1960,7 +1968,8 @@ int userfaultfd_register_range(struct userfaultfd_ctx *ctx,
 		new_flags = (vma->vm_flags & ~__VM_UFFD_FLAGS) | vm_flags;
 		vma = vma_modify_flags_uffd(&vmi, prev, vma, start, vma_end,
 					    new_flags,
-					    (struct vm_userfaultfd_ctx){ctx});
+					    (struct vm_userfaultfd_ctx){ctx},
+					    /* give_up_on_oom = */false);
 		if (IS_ERR(vma))
 			return PTR_ERR(vma);