From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753441AbcANNDv (ORCPT ); Thu, 14 Jan 2016 08:03:51 -0500 Received: from mx1.redhat.com ([209.132.183.28]:56665 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752882AbcANNDu (ORCPT ); Thu, 14 Jan 2016 08:03:50 -0500 From: "Jerome Marchand" To: Minchan Kim , Nitin Gupta Cc: Sergey Senozhatsky , linux-kernel@vger.kernel.org Subject: [PATCH] zram: don't call idr_remove() from zram_remove() Date: Thu, 14 Jan 2016 14:03:47 +0100 Message-Id: <1452776627-21662-1-git-send-email-jmarchan@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The use of idr_remove() is forbidden in the callback functions of idr_for_each(). It is therefore unsafe to call idr_remove in zram_remove(). This patch moves the call to idr_remove() from zram_remove() to hot_remove_store(). In the detroy_devices() path, idrs are removed by idr_destroy(). This solves an use-after-free detected by KASan. Signed-off-by: Jerome Marchand --- drivers/block/zram/zram_drv.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 47915d7..5e86e1d 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -1325,7 +1325,6 @@ static int zram_remove(struct zram *zram) pr_info("Removed device: %s\n", zram->disk->disk_name); - idr_remove(&zram_index_idr, zram->disk->first_minor); blk_cleanup_queue(zram->disk->queue); del_gendisk(zram->disk); put_disk(zram->disk); @@ -1367,9 +1366,10 @@ static ssize_t hot_remove_store(struct class *class, mutex_lock(&zram_index_mutex); zram = idr_find(&zram_index_idr, dev_id); - if (zram) + if (zram) { ret = zram_remove(zram); - else + idr_remove(&zram_index_idr, dev_id); + } else ret = -ENODEV; mutex_unlock(&zram_index_mutex); -- 2.5.0