Merge tag 'mm-hotfixes-stable-2025-03-17-20-09' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull misc hotfixes from Andrew Morton:
 "15 hotfixes. 7 are cc:stable and the remainder address post-6.13
  issues or aren't considered necessary for -stable kernels.

  13 are for MM and the other two are for squashfs and procfs.

  All are singletons. Please see the individual changelogs for details"

* tag 'mm-hotfixes-stable-2025-03-17-20-09' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  mm/page_alloc: fix memory accept before watermarks gets initialized
  mm: decline to manipulate the refcount on a slab page
  memcg: drain obj stock on cpu hotplug teardown
  mm/huge_memory: drop beyond-EOF folios with the right number of refs
  selftests/mm: run_vmtests.sh: fix half_ufd_size_MB calculation
  mm: fix error handling in __filemap_get_folio() with FGP_NOWAIT
  mm: memcontrol: fix swap counter leak from offline cgroup
  mm/vma: do not register private-anon mappings with khugepaged during mmap
  squashfs: fix invalid pointer dereference in squashfs_cache_delete
  mm/migrate: fix shmem xarray update during migration
  mm/hugetlb: fix surplus pages in dissolve_free_huge_page()
  mm/damon/core: initialize damos->walk_completed in damon_new_scheme()
  mm/damon: respect core layer filters' allowance decision on ops layer
  filemap: move prefaulting out of hot write path
  proc: fix UAF in proc_get_inode()

4 files changed, 19 insertions, 5 deletions

diff --git a/include/linux/damon.h b/include/linux/damon.h
index af525252b853..c9074d569596 100644
--- a/include/linux/damon.h
+++ b/include/linux/damon.h
@@ -470,6 +470,11 @@ struct damos {
 	unsigned long next_apply_sis;
 	/* informs if ongoing DAMOS walk for this scheme is finished */
 	bool walk_completed;
+	/*
+	 * If the current region in the filtering stage is allowed by core
+	 * layer-handled filters.  If true, operations layer allows it, too.
+	 */
+	bool core_filters_allowed;
 /* public: */
 	struct damos_quota quota;
 	struct damos_watermarks wmarks;
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 8483e09aeb2c..1f80baddacc5 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1458,7 +1458,10 @@ static inline void folio_get(struct folio *folio)
 
 static inline void get_page(struct page *page)
 {
-	folio_get(page_folio(page));
+	struct folio *folio = page_folio(page);
+	if (WARN_ON_ONCE(folio_test_slab(folio)))
+		return;
+	folio_get(folio);
 }
 
 static inline __must_check bool try_get_page(struct page *page)
@@ -1552,6 +1555,9 @@ static inline void put_page(struct page *page)
 {
 	struct folio *folio = page_folio(page);
 
+	if (folio_test_slab(folio))
+		return;
+
 	/*
 	 * For some devmap managed pages we need to catch refcount transition
 	 * from 2 to 1:
diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h
index 0b2a89854440..ea62201c74c4 100644
--- a/include/linux/proc_fs.h
+++ b/include/linux/proc_fs.h
@@ -20,10 +20,13 @@ enum {
 	 * If in doubt, ignore this flag.
 	 */
 #ifdef MODULE
-	PROC_ENTRY_PERMANENT = 0U,
+	PROC_ENTRY_PERMANENT		= 0U,
 #else
-	PROC_ENTRY_PERMANENT = 1U << 0,
+	PROC_ENTRY_PERMANENT		= 1U << 0,
 #endif
+
+	PROC_ENTRY_proc_read_iter	= 1U << 1,
+	PROC_ENTRY_proc_compat_ioctl	= 1U << 2,
 };
 
 struct proc_ops {
diff --git a/include/linux/swap_cgroup.h b/include/linux/swap_cgroup.h
index b5ec038069da..91cdf12190a0 100644
--- a/include/linux/swap_cgroup.h
+++ b/include/linux/swap_cgroup.h
@@ -6,7 +6,7 @@
 
 #if defined(CONFIG_MEMCG) && defined(CONFIG_SWAP)
 
-extern void swap_cgroup_record(struct folio *folio, swp_entry_t ent);
+extern void swap_cgroup_record(struct folio *folio, unsigned short id, swp_entry_t ent);
 extern unsigned short swap_cgroup_clear(swp_entry_t ent, unsigned int nr_ents);
 extern unsigned short lookup_swap_cgroup_id(swp_entry_t ent);
 extern int swap_cgroup_swapon(int type, unsigned long max_pages);
@@ -15,7 +15,7 @@ extern void swap_cgroup_swapoff(int type);
 #else
 
 static inline
-void swap_cgroup_record(struct folio *folio, swp_entry_t ent)
+void swap_cgroup_record(struct folio *folio, unsigned short id, swp_entry_t ent)
 {
 }