From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guoqing Jiang Subject: [PATCH 07/12] md-cluster: init suspend_list and suspend_lock early in join Date: Fri, 10 Jul 2015 17:01:18 +0800 Message-ID: <1436518883-12783-4-git-send-email-gqjiang@suse.com> References: <1436518453-12660-1-git-send-email-gqjiang@suse.com> <1436518883-12783-1-git-send-email-gqjiang@suse.com> Return-path: In-Reply-To: <1436518883-12783-1-git-send-email-gqjiang@suse.com> Sender: linux-raid-owner@vger.kernel.org To: neilb@suse.de Cc: rgoldwyn@suse.de, linux-raid@vger.kernel.org List-Id: linux-raid.ids If the node just join the cluster, and receive the msg from other nodes before init suspend_list, it will cause kernel crash due to NULL pointer dereference, so move the initializations early to fix the bug. md-cluster: Joined cluster 3578507b-e0cb-6d4f-6322-696cd7b1b10c slot 3 BUG: unable to handle kernel NULL pointer dereference at (null) ... ... ... Call Trace: [] process_recvd_msg+0x2e4/0x330 [md_cluster] [] recv_daemon+0x96/0x170 [md_cluster] [] md_thread+0x11d/0x170 [md_mod] [] kthread+0xb4/0xc0 [] ret_from_fork+0x7c/0xb0 ... ... ... RIP [] __remove_suspend_info+0x11/0xa0 [md_cluster] Signed-off-by: Guoqing Jiang --- drivers/md/md-cluster.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/md/md-cluster.c b/drivers/md/md-cluster.c index b80a689..6f1ea3c 100644 --- a/drivers/md/md-cluster.c +++ b/drivers/md/md-cluster.c @@ -671,6 +671,8 @@ static int join(struct mddev *mddev, int nodes) if (!cinfo) return -ENOMEM; + INIT_LIST_HEAD(&cinfo->suspend_list); + spin_lock_init(&cinfo->suspend_lock); init_completion(&cinfo->completion); mutex_init(&cinfo->sb_mutex); @@ -736,9 +738,6 @@ static int join(struct mddev *mddev, int nodes) goto err; } - INIT_LIST_HEAD(&cinfo->suspend_list); - spin_lock_init(&cinfo->suspend_lock); - ret = gather_all_resync_info(mddev, nodes); if (ret) goto err; -- 1.7.12.4