The patch titled Subject: zram: fix uninitialized ZRAM not releasing backing device has been added to the -mm mm-hotfixes-unstable branch. Its filename is zram-fix-uninitialized-zram-not-releasing-backing-device.patch

This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches...

This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------ From: Kairui Song kasong@tencent.com Subject: zram: fix uninitialized ZRAM not releasing backing device Date: Tue, 10 Dec 2024 00:57:16 +0800

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 Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---

drivers/block/zram/zram_drv.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-)

--- a/drivers/block/zram/zram_drv.c~zram-fix-uninitialized-zram-not-releasing-backing-device +++ a/drivers/block/zram/zram_drv.c @@ -1444,12 +1444,16 @@ 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) @@ -2334,11 +2338,6 @@ 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);

_

Patches currently in -mm which might be from kasong@tencent.com are

zram-refuse-to-use-zero-sized-block-device-as-backing-device.patch zram-fix-uninitialized-zram-not-releasing-backing-device.patch