Re: [PATCH V2 3/3] nvmet-tcp: fix memory leak when performing a controller reset

Sagi Grimberg
2021-11-16T09:07:39Z

> If a reset controller is executed while the initiator
> is performing some I/O the driver may leak the memory allocated
> for the commands' iovec.
>
> Make sure that nvmet_tcp_uninit_data_in_cmds() releases
> all the memory.
>
> Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
> ---
> drivers/nvme/target/tcp.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c
> index 028b47ff0f0f..5a238fa067cd 100644
> --- a/drivers/nvme/target/tcp.c
> +++ b/drivers/nvme/target/tcp.c
> @@ -1427,7 +1427,10 @@ static void nvmet_tcp_uninit_data_in_cmds(struct nvmet_tcp_queue *queue)
>
> for (i = 0; i < queue->nr_cmds; i++, cmd++) {
> if (nvmet_tcp_need_data_in(cmd))
> - nvmet_tcp_finish_cmd(cmd);
> + nvmet_req_uninit(&cmd->req);
> +
> + nvmet_tcp_unmap_pdu_iovec(cmd);
> + nvmet_tcp_free_iovec(cmd);

I understand how unmap_pdu_iovec is re-entrance safe, but sgl_free
called from free_iovec is not. What prevents it from being called
for commands that have already freed their sgls?