From: Kairui Song Date: Mon, 9 Dec 2024 16:57:16 +0000 (+0800) Subject: zram: fix uninitialized ZRAM not releasing backing device X-Git-Tag: v6.1.122~25 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ac3b5366b9b7c9d97b606532ceab43d2329a22f3;p=thirdparty%2Fkernel%2Fstable.git 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 Reported-by: Desheng Wu Suggested-by: Sergey Senozhatsky Reviewed-by: Sergey Senozhatsky Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 102c78cfc0dbd..b83181357f36d 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -1168,12 +1168,16 @@ 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) @@ -1722,11 +1726,6 @@ 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);