Merge tag 'mm-hotfixes-stable-2025-05-25-00-58' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull hotfixes from Andrew Morton:
 "22 hotfixes.

  13 are cc:stable and the remainder address post-6.14 issues or aren't
  considered necessary for -stable kernels. 19 are for MM"

* tag 'mm-hotfixes-stable-2025-05-25-00-58' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (22 commits)
  mailmap: add Jarkko's employer email address
  mm: fix copy_vma() error handling for hugetlb mappings
  memcg: always call cond_resched() after fn()
  mm/hugetlb: fix kernel NULL pointer dereference when replacing free hugetlb folios
  mm: vmalloc: only zero-init on vrealloc shrink
  mm: vmalloc: actually use the in-place vrealloc region
  alloc_tag: allocate percpu counters for module tags dynamically
  module: release codetag section when module load fails
  mm/cma: make detection of highmem_start more robust
  MAINTAINERS: add mm memory policy section
  MAINTAINERS: add mm ksm section
  kasan: avoid sleepable page allocation from atomic context
  highmem: add folio_test_partial_kmap()
  MAINTAINERS: add hung-task detector section
  taskstats: fix struct taskstats breaks backward compatibility since version 15
  mm/truncate: fix out-of-bounds when doing a right-aligned split
  MAINTAINERS: add mm reclaim section
  MAINTAINERS: update page allocator section
  mm: fix VM_UFFD_MINOR == VM_SHADOW_STACK on USERFAULTFD=y && ARM64_GCS=y
  mm: mmap: map MAP_STACK to VM_NOHUGEPAGE only if THP is enabled
  ...

1 files changed, 8 insertions, 5 deletions

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 2d7511654831..00cf1b575c89 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -4093,8 +4093,8 @@ void *vrealloc_noprof(const void *p, size_t size, gfp_t flags)
 	 * would be a good heuristic for when to shrink the vm_area?
 	 */
 	if (size <= old_size) {
-		/* Zero out "freed" memory. */
-		if (want_init_on_free())
+		/* Zero out "freed" memory, potentially for future realloc. */
+		if (want_init_on_free() || want_init_on_alloc(flags))
 			memset((void *)p + size, 0, old_size - size);
 		vm->requested_size = size;
 		kasan_poison_vmalloc(p + size, old_size - size);
@@ -4107,10 +4107,13 @@ void *vrealloc_noprof(const void *p, size_t size, gfp_t flags)
 	if (size <= alloced_size) {
 		kasan_unpoison_vmalloc(p + old_size, size - old_size,
 				       KASAN_VMALLOC_PROT_NORMAL);
-		/* Zero out "alloced" memory. */
-		if (want_init_on_alloc(flags))
-			memset((void *)p + old_size, 0, size - old_size);
+		/*
+		 * No need to zero memory here, as unused memory will have
+		 * already been zeroed at initial allocation time or during
+		 * realloc shrink time.
+		 */
 		vm->requested_size = size;
+		return (void *)p;
 	}
 
 	/* TODO: Grow the vm_area, i.e. allocate and map additional pages. */