[PATCH 6.12 110/160] zram: fix uninitialized ZRAM not releasing backing device

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6.12-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Kairui Song <kasong@xxxxxxxxxxx>

commit 74363ec674cb172d8856de25776c8f3103f05e2f upstream.

Setting backing device is done before ZRAM initialization.  If we set the
backing device, then remove the ZRAM module without initializing the
device, the backing device reference will be leaked and the device will be
hold forever.

Fix this by always reset the ZRAM fully on rmmod or reset store.

Link: https://lkml.kernel.org/r/20241209165717.94215-3-ryncsn@xxxxxxxxx
Fixes: 013bf95a83ec ("zram: add interface to specif backing device")
Signed-off-by: Kairui Song <kasong@xxxxxxxxxxx>
Reported-by: Desheng Wu <deshengwu@xxxxxxxxxxx>
Suggested-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
Reviewed-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/block/zram/zram_drv.c |    9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -1325,12 +1325,16 @@ static void zram_meta_free(struct zram *
 	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)
@@ -2171,11 +2175,6 @@ static void zram_reset_device(struct zra
 
 	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);
 






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