diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index 87b0b78249da..ad39ab95ea66 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -52,6 +52,7 @@ static DEFINE_IDR(nbd_index_idr); static DEFINE_MUTEX(nbd_index_mutex); static struct workqueue_struct *nbd_del_wq; +static struct cred *nbd_cred; static int nbd_total_devices = 0; struct nbd_sock { @@ -554,6 +555,7 @@ static int __sock_xmit(struct nbd_device *nbd, struct socket *sock, int send, int result; struct msghdr msg = {} ; unsigned int noreclaim_flag; + const struct cred *old_cred; if (unlikely(!sock)) { dev_err_ratelimited(disk_to_dev(nbd->disk), @@ -562,6 +564,8 @@ static int __sock_xmit(struct nbd_device *nbd, struct socket *sock, int send, return -EINVAL; } + old_cred = override_creds(nbd_cred); + msg.msg_iter = *iter; noreclaim_flag = memalloc_noreclaim_save(); @@ -586,6 +590,8 @@ static int __sock_xmit(struct nbd_device *nbd, struct socket *sock, int send, memalloc_noreclaim_restore(noreclaim_flag); + revert_creds(old_cred); + return result; } @@ -2677,7 +2683,15 @@ static int __init nbd_init(void) return -ENOMEM; } + nbd_cred = prepare_kernel_cred(&init_task); + if (!nbd_cred) { + destroy_workqueue(nbd_del_wq); + unregister_blkdev(NBD_MAJOR, "nbd"); + return -ENOMEM; + } + if (genl_register_family(&nbd_genl_family)) { + put_cred(nbd_cred); destroy_workqueue(nbd_del_wq); unregister_blkdev(NBD_MAJOR, "nbd"); return -EINVAL; @@ -2732,6 +2746,7 @@ static void __exit nbd_cleanup(void) /* Also wait for nbd_dev_remove_work() completes */ destroy_workqueue(nbd_del_wq); + put_cred(nbd_cred); idr_destroy(&nbd_index_idr); unregister_blkdev(NBD_MAJOR, "nbd"); }