From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965307AbbHKPof (ORCPT ); Tue, 11 Aug 2015 11:44:35 -0400 Received: from mail-pd0-f170.google.com ([209.85.192.170]:34853 "EHLO mail-pd0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755290AbbHKPoe (ORCPT ); Tue, 11 Aug 2015 11:44:34 -0400 From: Sergey Senozhatsky To: Andrew Morton , Minchan Kim Cc: linux-kernel@vger.kernel.org, Sergey Senozhatsky , Sergey Senozhatsky Subject: [PATCH v2] zram: fix pool name truncation Date: Wed, 12 Aug 2015 00:43:29 +0900 Message-Id: <1439307809-914-1-git-send-email-sergey.senozhatsky@gmail.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1439299983-8070-1-git-send-email-sergey.senozhatsky@gmail.com> References: <1439299983-8070-1-git-send-email-sergey.senozhatsky@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org zram_meta_alloc() constructs a pool name for zs_create_pool() call as snprintf(pool_name, sizeof(pool_name), "zram%d", device_id); However, it defines pool name buffer to be only 8 chars long (minus trailing zero), which means that we can have only 1000 pool names: zram0 -- zram999. With CONFIG_ZSMALLOC_STAT enabled an attempt to create a device zram1000 can fail if device zram100 already exists, because snprintf() will truncate new pool name to zram100 and pass it to debugfs_create_dir(), causing: debugfs dir creation failed zram: Error creating memory pool ... and so on (zram101 - zram1010, etc). Fix it by increasing pool_name buffer size to 15: -- zram prefix (length 4) -- int device_id can use up to 10 chars -- terminating zero byte Signed-off-by: Sergey Senozhatsky --- drivers/block/zram/zram_drv.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index b088ca9..1dec01d 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -502,7 +502,7 @@ static void zram_meta_free(struct zram_meta *meta, u64 disksize) static struct zram_meta *zram_meta_alloc(int device_id, u64 disksize) { size_t num_pages; - char pool_name[8]; + char pool_name[15]; struct zram_meta *meta = kmalloc(sizeof(*meta), GFP_KERNEL); if (!meta) -- 2.5.0