From mboxrd@z Thu Jan 1 00:00:00 1970 From: lixiaokeng Subject: [PATCH 07/14] libmultipath: check return value of dm_mapname in, sysfs_check_holders Date: Wed, 2 Sep 2020 15:19:51 +0800 Message-ID: References: <37544d4c-950f-4281-3b66-e4d1884c5167@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <37544d4c-950f-4281-3b66-e4d1884c5167@huawei.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com Content-Language: en-GB To: Martin Wilck , Benjamin Marzinski , Christophe Varoqui , dm-devel mailing list Cc: linfeilong , "liuzhiqiang (I)" List-Id: dm-devel.ids In sysfs_check_holders func, table_name is obtained by calling dm_mapname func, and then call dm_reassign_table for reassigning table. However, we donnot check whether dm_mapname func returns NULL, and then it may cause a segmentation fault in dm_task_set_name. Here, we will check whether dm_mapname func returns NULL before using it. Signed-off-by: Zhiqiang Liu Signed-off-by: Lixiaokeng --- libmultipath/sysfs.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/libmultipath/sysfs.c b/libmultipath/sysfs.c index 12a82d95..5390de62 100644 --- a/libmultipath/sysfs.c +++ b/libmultipath/sysfs.c @@ -278,7 +278,11 @@ int sysfs_check_holders(char * check_devt, char * new_devt) continue; } table_name = dm_mapname(major, table_minor); - + if (!table_name) { + condlog(2, "%s: mapname not found for %d:%d", check_dev, + major, table_minor); + continue; + } condlog(0, "%s: reassign table %s old %s new %s", check_dev, table_name, check_devt, new_devt); --