ceph: protect access to d_parent
d_parent is protected by d_lock: use it when looking up a dentry's parent
directory inode. Also take a reference and drop it in the caller to avoid
a use-after-free.
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Reviewed-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 2717dc4..a7db56f 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -1562,7 +1562,7 @@
{
struct inode *inode = dentry->d_inode;
struct ceph_inode_info *ci = ceph_inode(inode);
- struct inode *parent_inode = dentry->d_parent->d_inode;
+ struct inode *parent_inode;
const unsigned int ia_valid = attr->ia_valid;
struct ceph_mds_request *req;
struct ceph_mds_client *mdsc = ceph_sb_to_client(dentry->d_sb)->mdsc;
@@ -1745,7 +1745,9 @@
req->r_inode_drop = release;
req->r_args.setattr.mask = cpu_to_le32(mask);
req->r_num_caps = 1;
+ parent_inode = ceph_get_dentry_parent_inode(dentry);
err = ceph_mdsc_do_request(mdsc, parent_inode, req);
+ iput(parent_inode);
}
dout("setattr %p result=%d (%s locally, %d remote)\n", inode, err,
ceph_cap_string(dirtied), mask);