Joseph Qi
2014-Mar-21 07:41 UTC
[Ocfs2-devel] [PATCH v2] ocfs2: fix dead lock risk when kmalloc failed in dlm_query_region_handler
From: Zhonghua Guo <guozhonghua at h3c.com>
In dlm_query_region_handler(), once kmalloc failed, it will unlock
dlm_domain_lock without lock first, then dead lock happens.
Signed-off-by: Zhonghua Guo <guozhonghua at h3c.com>
Signed-off-by: Joseph Qi <joseph.qi at huawei.com>
Reviewed-by: Srinivas Eeda <srinivas.eeda at oracle.com>
Reviewed-by: Andrew Morton <akpm at linux-foundation.org>
Tested-by: Joseph Qi <joseph.qi at huawei.com>
---
fs/ocfs2/dlm/dlmdomain.c | 21 +++++++++------------
1 file changed, 9 insertions(+), 12 deletions(-)
diff --git a/fs/ocfs2/dlm/dlmdomain.c b/fs/ocfs2/dlm/dlmdomain.c
index 33660a4..01c4e9e 100644
--- a/fs/ocfs2/dlm/dlmdomain.c
+++ b/fs/ocfs2/dlm/dlmdomain.c
@@ -1123,7 +1123,6 @@ static int dlm_query_region_handler(struct o2net_msg *msg,
u32 len,
struct dlm_ctxt *dlm = NULL;
char *local = NULL;
int status = 0;
- int locked = 0;
qr = (struct dlm_query_region *) msg->buf;
@@ -1132,10 +1131,8 @@ static int dlm_query_region_handler(struct o2net_msg
*msg, u32 len,
/* buffer used in dlm_mast_regions() */
local = kmalloc(sizeof(qr->qr_regions), GFP_KERNEL);
- if (!local) {
- status = -ENOMEM;
- goto bail;
- }
+ if (!local)
+ return -ENOMEM;
status = -EINVAL;
@@ -1144,16 +1141,15 @@ static int dlm_query_region_handler(struct o2net_msg
*msg, u32 len,
if (!dlm) {
mlog(ML_ERROR, "Node %d queried hb regions on domain %s "
"before join domain\n", qr->qr_node, qr->qr_domain);
- goto bail;
+ goto out_domain_lock;
}
spin_lock(&dlm->spinlock);
- locked = 1;
if (dlm->joining_node != qr->qr_node) {
mlog(ML_ERROR, "Node %d queried hb regions on domain %s "
"but joining node is %d\n", qr->qr_node, qr->qr_domain,
dlm->joining_node);
- goto bail;
+ goto out_dlm_lock;
}
/* Support for global heartbeat was added in 1.1 */
@@ -1163,14 +1159,15 @@ static int dlm_query_region_handler(struct o2net_msg
*msg, u32 len,
"but active dlm protocol is %d.%d\n", qr->qr_node,
qr->qr_domain, dlm->dlm_locking_proto.pv_major,
dlm->dlm_locking_proto.pv_minor);
- goto bail;
+ goto out_dlm_lock;
}
status = dlm_match_regions(dlm, qr, local, sizeof(qr->qr_regions));
-bail:
- if (locked)
- spin_unlock(&dlm->spinlock);
+out_dlm_lock:
+ spin_unlock(&dlm->spinlock);
+
+out_domain_lock:
spin_unlock(&dlm_domain_lock);
kfree(local);
--
1.8.4.3