From: Sergey Senozhatsky <senozhatsky@chromium.org>
Date: Fri, 21 Feb 2025 22:25:47 +0000 (+0900)
Subject: zram: do not leak page on writeback_store error path
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=2c5cbb06c0188e4279cb794b2a0a6f3593b9fdd2;p=users%2Fjedix%2Flinux-maple.git

zram: do not leak page on writeback_store error path

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

Link: https://lkml.kernel.org/r/20250221222958.2225035-17-senozhatsky@chromium.org
Fixes: 330edc2bc059 (zram: rework writeback target selection strategy)
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
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 1da329cae8ce..4e9381b153da 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -792,7 +792,7 @@ static ssize_t writeback_store(struct device *dev,
 	unsigned long index = 0;
 	struct bio bio;
 	struct bio_vec bio_vec;
-	struct page *page;
+	struct page *page = NULL;
 	ssize_t ret = len;
 	int mode, err;
 	unsigned long blk_idx = 0;
@@ -934,8 +934,10 @@ next:
 
 	if (blk_idx)
 		free_block_bdev(zram, blk_idx);
-	__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);