Merge tag 'mm-hotfixes-stable-2024-12-21-12-09' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull misc fixes from Andrew Morton:
 "25 hotfixes.  16 are cc:stable.  19 are MM and 6 are non-MM.

  The usual bunch of singletons and doubletons - please see the relevant
  changelogs for details"

* tag 'mm-hotfixes-stable-2024-12-21-12-09' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (25 commits)
  mm: huge_memory: handle strsep not finding delimiter
  alloc_tag: fix set_codetag_empty() when !CONFIG_MEM_ALLOC_PROFILING_DEBUG
  alloc_tag: fix module allocation tags populated area calculation
  mm/codetag: clear tags before swap
  mm/vmstat: fix a W=1 clang compiler warning
  mm: convert partially_mapped set/clear operations to be atomic
  nilfs2: fix buffer head leaks in calls to truncate_inode_pages()
  vmalloc: fix accounting with i915
  mm/page_alloc: don't call pfn_to_page() on possibly non-existent PFN in split_large_buddy()
  fork: avoid inappropriate uprobe access to invalid mm
  nilfs2: prevent use of deleted inode
  zram: fix uninitialized ZRAM not releasing backing device
  zram: refuse to use zero sized block device as backing device
  mm: use clear_user_(high)page() for arch with special user folio handling
  mm: introduce cpu_icache_is_aliasing() across all architectures
  mm: add RCU annotation to pte_offset_map(_lock)
  mm: correctly reference merged VMA
  mm: use aligned address in copy_user_gigantic_page()
  mm: use aligned address in clear_gigantic_page()
  mm: shmem: fix ShmemHugePages at swapout
  ...

1 files changed, 10 insertions, 5 deletions

diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 3dee026988dc..45df5eeabc5e 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -614,6 +614,12 @@ static ssize_t backing_dev_store(struct device *dev,
 	}
 
 	nr_pages = i_size_read(inode) >> PAGE_SHIFT;
+	/* Refuse to use zero sized device (also prevents self reference) */
+	if (!nr_pages) {
+		err = -EINVAL;
+		goto out;
+	}
+
 	bitmap_sz = BITS_TO_LONGS(nr_pages) * sizeof(long);
 	bitmap = kvzalloc(bitmap_sz, GFP_KERNEL);
 	if (!bitmap) {
@@ -1438,12 +1444,16 @@ static void zram_meta_free(struct zram *zram, u64 disksize)
 	size_t num_pages = disksize >> PAGE_SHIFT;
 	size_t index;
 
+	if (!zram->table)
+		return;
+
 	/* Free all pages that are still in this zram device */
 	for (index = 0; index < num_pages; index++)
 		zram_free_page(zram, index);
 
 	zs_destroy_pool(zram->mem_pool);
 	vfree(zram->table);
+	zram->table = NULL;
 }
 
 static bool zram_meta_alloc(struct zram *zram, u64 disksize)
@@ -2320,11 +2330,6 @@ static void zram_reset_device(struct zram *zram)
 
 	zram->limit_pages = 0;
 
-	if (!init_done(zram)) {
-		up_write(&zram->init_lock);
-		return;
-	}
-
 	set_capacity_and_notify(zram->disk, 0);
 	part_stat_set_all(zram->disk->part0, 0);