fs/9p: Add fid before dentry instantiation
commit 5441ae5eb3614d3c28f77073370738a2820c88e4 upstream.
d_instantiate marks the dentry positive. So a parallel lookup and mkdir of
the directory can find dentry that doesn't have fid attached. This can result
in both the code path doing v9fs_fid_add which results in v9fs_dentry leak.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 35d4121..ad7aae4 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -633,13 +633,11 @@
P9_DPRINTK(P9_DEBUG_VFS, "inode creation failed %d\n", err);
goto error;
}
- d_instantiate(dentry, inode);
err = v9fs_fid_add(dentry, fid);
if (err < 0)
goto error;
-
+ d_instantiate(dentry, inode);
return ofid;
-
error:
if (ofid)
p9_client_clunk(ofid);