zram: do not leak page on recompress_store error path

Ensure the page used for local object data is freed on error out path.

Link: https://lkml.kernel.org/r/20250303022425.285971-18-senozhatsky@chromium.org
Fixes: 3f909a60cec1 ("zram: rework recompress target selection strategy")
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Kairui Song <ryncsn@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Yosry Ahmed <yosry.ahmed@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 62aef12417a43e3dde05116e43a83c5c9b2d7e34..e50a5a216974a2d67fe09a82f6ddc719d492fa68 100644 (file)
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -2013,7 +2013,7 @@ static ssize_t recompress_store(struct device *dev,
        struct zram_pp_slot *pps;
        u32 mode = 0, threshold = 0;
        u32 prio, prio_max;
-       struct page *page;
+       struct page *page = NULL;
        ssize_t ret;
 
        prio = ZRAM_SECONDARY_COMP;
@@ -2157,9 +2157,9 @@ next:
                cond_resched();
        }
 
-       __free_page(page);
-
 release_init_lock:
+       if (page)
+               __free_page(page);
        release_pp_ctl(zram, ctl);
        atomic_set(&zram->pp_in_progress, 0);
        up_read(&zram->init_lock);