From 6fb92e9a52e3feae309a213950f21dfcd1eb0b40 Mon Sep 17 00:00:00 2001
From: Kairui Song <kasong@tencent.com>
Date: Tue, 10 Dec 2024 00:57:16 +0800
Subject: [PATCH] zram: fix uninitialized ZRAM not releasing backing device
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@gmail.com
Fixes: 013bf95a83ec ("zram: add interface to specif backing device")
Signed-off-by: Kairui Song <kasong@tencent.com>
Reported-by: Desheng Wu <deshengwu@tencent.com>
Suggested-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/block/zram/zram_drv.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 9fcbaca8e2ad9..bf83a104086cc 100644
--- 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 *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)
@@ -2171,11 +2175,6 @@ 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);
--
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