From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joseph Qi Date: Tue, 11 Feb 2014 20:15:02 +0800 Subject: [Ocfs2-devel] [PATCH] ocfs2: fix null pointer dereference when access dlm_state before launching dlm thread Message-ID: <52FA1446.7030704@huawei.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ocfs2-devel@oss.oracle.com From: Zongxun Wang When mounting an ocfs2 volume, it will firstly generate a file /sys/kernel/debug/o2dlm//dlm_state, and then launch the dlm thread. So the following situation will cause a null pointer dereference. dlm_debug_init -> access file dlm_state which will call dlm_state_print -> dlm_launch_thread Move dlm_debug_init after dlm_launch_thread and dlm_launch_recovery_thread can fix this issue. Signed-off-by: Zongxun Wang Signed-off-by: Joseph Qi --- fs/ocfs2/dlm/dlmdomain.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/fs/ocfs2/dlm/dlmdomain.c b/fs/ocfs2/dlm/dlmdomain.c index 33660a4..1307a8c 100644 --- a/fs/ocfs2/dlm/dlmdomain.c +++ b/fs/ocfs2/dlm/dlmdomain.c @@ -1877,19 +1877,19 @@ static int dlm_join_domain(struct dlm_ctxt *dlm) goto bail; } - status = dlm_debug_init(dlm); + status = dlm_launch_thread(dlm); if (status < 0) { mlog_errno(status); goto bail; } - status = dlm_launch_thread(dlm); + status = dlm_launch_recovery_thread(dlm); if (status < 0) { mlog_errno(status); goto bail; } - status = dlm_launch_recovery_thread(dlm); + status = dlm_debug_init(dlm); if (status < 0) { mlog_errno(status); goto bail; -- 1.8.4.3