On 05/04/2018 11:02 AM, Jianchao Wang wrote:
When nvme_init_identify in nvme_rdma_configure_admin_queue fails,
the ctrl->queues[0] is freed but the NVME_RDMA_Q_LIVE is still set.
If nvme_rdma_stop_queue is invoked, we will incur use-after-free
which will cause memory corruption.
BUG: KASAN: use-after-free in rdma_disconnect+0x1f/0xe0 [rdma_cm]
Read of size 8 at addr ffff8801dc3969c0 by task kworker/u16:3/9304
CPU: 3 PID: 9304 Comm: kworker/u16:3 Kdump: loaded Tainted: G W
4.17.0-rc3+ #20
Workqueue: nvme-delete-wq nvme_delete_ctrl_work
Call Trace:
dump_stack+0x91/0xeb
print_address_description+0x6b/0x290
kasan_report+0x261/0x360
rdma_disconnect+0x1f/0xe0 [rdma_cm]
nvme_rdma_stop_queue+0x25/0x40 [nvme_rdma]
nvme_rdma_shutdown_ctrl+0xf3/0x150 [nvme_rdma]
nvme_delete_ctrl_work+0x98/0xe0
process_one_work+0x3ca/0xaa0
worker_thread+0x4e2/0x6c0
kthread+0x18d/0x1e0
ret_from_fork+0x24/0x30
To fix it, clear the NVME_RDMA_Q_LIVE before free the ctrl->queues[0].
The queue will be freed, so it certainly is not LIVE any more.
Signed-off-by: Jianchao Wang <jianchao.w.w...@oracle.com>
---
drivers/nvme/host/rdma.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c
index fd965d0..ffbfe82 100644
--- a/drivers/nvme/host/rdma.c
+++ b/drivers/nvme/host/rdma.c
@@ -812,6 +812,11 @@ static int nvme_rdma_configure_admin_queue(struct
nvme_rdma_ctrl *ctrl,
if (new)
nvme_rdma_free_tagset(&ctrl->ctrl, ctrl->ctrl.admin_tagset);
out_free_queue:
+ /*
+ * The queue will be freed, so it is not LIVE any more.
+ * This could avoid use-after-free in nvme_rdma_stop_queue.
+ */
+ clear_bit(NVME_RDMA_Q_LIVE, &ctrl->queues[0].flags);
nvme_rdma_free_queue(&ctrl->queues[0]);
return error;
}
The correct fix would be to add a tag for stop_queue and call
nvme_rdma_stop_queue() in all the failure cases after
nvme_rdma_start_queue.
